Improper encoding of non-finite floating-point values during MapMessage JSON serialization in Apache Log4j API produces output that is not valid JSON. This issue affects Apache Log4j API versions 2.13.1 through 2.25.4 and version 2.26.0. The fix for CVE-2026-34481 did not cover all code paths: when a MapMessage contains a non-finite IEEE 754 value (NaN, Infinity, or -Infinity), MapMessage.asJson() emits the corresponding bare token. RFC 8259 does not permit these tokens, so a conformant parser rejects the resulting document. The defect is reachable only when both of the following conditions hold: * The application uses the message resolver https://logging.apache.org/log4j/2.x/manual/json-template-layout.html#event-template-resolver-message of JsonTemplateLayout or any other layout that relies on MapMessage.asJson() or MapMessage.getFormattedMessage(new String[]{"JSON"}). * The application logs a MapMessage that contains an attacker-controlled floating-point value. An attacker who can supply a non-finite value can cause the affected layout to emit malformed JSON, which may corrupt the enclosing log record or disrupt downstream log ingestion and parsing. Users are advised to upgrade to Apache Log4j API 2.25.5 or 2.26.1, both of which emit RFC 8259-compliant JSON for non-finite values.

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - Improper encoding of non-finite floating-point values during MapMessage JSON serialization in Apache Log4j
    API produces output that is not valid JSON. This issue affects Apache Log4j API versions 2.13.1 through
    2.25.4 and version 2.26.0. The fix for CVE-2026-34481 did not cover all code paths: when a MapMessage
    contains a non-finite IEEE 754 value (NaN, Infinity, or -Infinity), MapMessage.asJson() emits the
    corresponding bare token. RFC 8259 does not permit these tokens, so a conformant parser rejects the
    resulting document. The defect is reachable only when both of the following conditions hold: * The
    application uses the message resolver https://logging.apache.org/log4j/2.x/manual/json-template-
    layout.html#event-template-resolver-message of JsonTemplateLayout or any other layout that relies on
    MapMessage.asJson() or MapMessage.getFormattedMessage(new String[]{"JSON"}). * The application logs a
    MapMessage that contains an attacker-controlled floating-point value. An attacker who can supply a non-
    finite value can cause the affected layout to emit malformed JSON, which may corrupt the enclosing log
    record or disrupt downstream log ingestion and parsing. Users are advised to upgrade to Apache Log4j API
    2.25.5 or 2.26.1, both of which emit RFC 8259-compliant JSON for non-finite values. (CVE-2026-49844)

The AlmaLinux 9.6 host has packages installed that are affected by a vulnerability as referenced in the TuxCare ALMALINUX9.6:CLSA-2026:1784624635 advisory.

  - Improper encoding of non-finite floating-point values during MapMessage JSON serialization in Apache Log4j     API produces output that is not valid JSON. This issue affects Apache Log4j API versions 2.13.1 through     2.25.4 and version 2.26.0. The fix for CVE-2026-34481 did not cover all code paths: when a MapMessage     contains a non-finite IEEE 754 value (NaN, Infinity, or -Infinity), MapMessage.asJson() emits the     corresponding bare token. RFC 8259 does not permit these tokens, so a conformant parser rejects the     resulting document. The defect is reachable only when both of the following conditions hold: * The     application uses the message resolver https://logging.apache.org/log4j/2.x/manual/json-template-     layout.html#event-template-resolver-message of JsonTemplateLayout or any other layout that relies on     MapMessage.asJson() or MapMessage.getFormattedMessage(new String[]{JSON}). * The application logs a     MapMessage that contains an attacker-controlled floating-point value. An attacker who can supply a non-     finite value can cause the affected layout to emit malformed JSON, which may corrupt the enclosing log     record or disrupt downstream log ingestion and parsing. Users are advised to upgrade to Apache Log4j API     2.25.5 or 2.26.1, both of which emit RFC 8259-compliant JSON for non-finite values. (CVE-2026-49844)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The Rocky Linux 9.6 host has packages installed that are affected by a vulnerability as referenced in the TuxCare ALMALINUX9.6:CLSA-2026:1784624635 advisory.

  - Improper encoding of non-finite floating-point values during MapMessage JSON serialization in Apache Log4j     API produces output that is not valid JSON. This issue affects Apache Log4j API versions 2.13.1 through     2.25.4 and version 2.26.0. The fix for CVE-2026-34481 did not cover all code paths: when a MapMessage     contains a non-finite IEEE 754 value (NaN, Infinity, or -Infinity), MapMessage.asJson() emits the     corresponding bare token. RFC 8259 does not permit these tokens, so a conformant parser rejects the     resulting document. The defect is reachable only when both of the following conditions hold: * The     application uses the message resolver https://logging.apache.org/log4j/2.x/manual/json-template-     layout.html#event-template-resolver-message of JsonTemplateLayout or any other layout that relies on     MapMessage.asJson() or MapMessage.getFormattedMessage(new String[]{JSON}). * The application logs a     MapMessage that contains an attacker-controlled floating-point value. An attacker who can supply a non-     finite value can cause the affected layout to emit malformed JSON, which may corrupt the enclosing log     record or disrupt downstream log ingestion and parsing. Users are advised to upgrade to Apache Log4j API     2.25.5 or 2.26.1, both of which emit RFC 8259-compliant JSON for non-finite values. (CVE-2026-49844)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The AlmaLinux 9.2 host has packages installed that are affected by a vulnerability as referenced in the TuxCare ALMALINUX9.2:CLSA-2026:1787235852 advisory.

  - Improper encoding of non-finite floating-point values during MapMessage JSON serialization in Apache Log4j     API produces output that is not valid JSON. This issue affects Apache Log4j API versions 2.13.1 through     2.25.4 and version 2.26.0. The fix for CVE-2026-34481 did not cover all code paths: when a MapMessage     contains a non-finite IEEE 754 value (NaN, Infinity, or -Infinity), MapMessage.asJson() emits the     corresponding bare token. RFC 8259 does not permit these tokens, so a conformant parser rejects the     resulting document. The defect is reachable only when both of the following conditions hold: * The     application uses the message resolver https://logging.apache.org/log4j/2.x/manual/json-template-     layout.html#event-template-resolver-message of JsonTemplateLayout or any other layout that relies on     MapMessage.asJson() or MapMessage.getFormattedMessage(new String[]{JSON}). * The application logs a     MapMessage that contains an attacker-controlled floating-point value. An attacker who can supply a non-     finite value can cause the affected layout to emit malformed JSON, which may corrupt the enclosing log     record or disrupt downstream log ingestion and parsing. Users are advised to upgrade to Apache Log4j API     2.25.5 or 2.26.1, both of which emit RFC 8259-compliant JSON for non-finite values. (CVE-2026-49844)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The 13.5.0.0 and 24.1.0.0 versions of Enterprise Manager Cloud Control installed on the remote host are affected by multiple vulnerabilities as referenced in the September 2026 CSPU advisory.

  - Vulnerability in the Oracle Enterprise Manager Base Platform product of Oracle Enterprise Manager     (component: Agent Next Gen (Apache Mina)). Supported versions that are affected are 13.5 and 24.1. Easily     exploitable vulnerability allows unauthenticated attacker with network access via HTTP to compromise Oracle     Enterprise Manager Base Platform. Successful attacks of this vulnerability can result in takeover of Oracle     Enterprise Manager Base Platform. (CVE-2026-41635)

  - Vulnerability in the Oracle Enterprise Manager for Fusion Middleware product of Oracle Enterprise Manager     (component: Metrics). Supported versions that are affected are 13.5 and 24.1. Easily exploitable     vulnerability allows unauthenticated attacker with network access via HTTP to compromise Oracle Enterprise     Manager for Fusion Middleware. Successful attacks of this vulnerability can result in takeover of Oracle     Enterprise Manager for Fusion Middleware. (CVE-2026-83355)

  - Vulnerability in the Oracle Enterprise Manager Base Platform product of Oracle Enterprise Manager     (component: OMS (Eclipse Jetty)). The supported version that is affected is 24.1. Easily exploitable     vulnerability allows unauthenticated attacker with network access via HTTP to compromise Oracle Enterprise     Manager Base Platform. (CVE-2026-2332)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

It is, therefore, affected by a vulnerability as referenced in the ALAS2023-2026-2072 advisory.

    Improper encoding of non-finite floating-point values during MapMessage JSON serialization in Apache Log4j     API produces output that is not valid JSON. This issue affects Apache Log4j API versions 2.13.1 through     2.25.4 and version 2.26.0.

    The fix for CVE-2026-34481 did not cover all code paths: when a MapMessage contains a non-finite IEEE 754     value (NaN, Infinity, or -Infinity), MapMessage.asJson() emits the corresponding bare token. RFC 8259 does     not permit these tokens, so a conformant parser rejects the resulting document.

    The defect is reachable only when both of the following conditions hold:

    *  The application uses the  message resolver https://logging.apache.org/log4j/2.x/manual/json-template-     layout.html#event-template-resolver-message  of JsonTemplateLayout or any other layout that relies on     MapMessage.asJson() or MapMessage.getFormattedMessage(new String[]{JSON}).*  The application logs a     MapMessage that contains an attacker-controlled floating-point value.

    An attacker who can supply a non-finite value can cause the affected layout to emit malformed JSON, which     may corrupt the enclosing log record or disrupt downstream log ingestion and parsing.

    Users are advised to upgrade to Apache Log4j API 2.25.5 or 2.26.1, both of which emit RFC 8259-compliant     JSON for non-finite values. (CVE-2026-49844)

Tenable has extracted the preceding description block directly from the tested product security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The version of AOS installed on the remote host is prior to 7.6.0.6. It is, therefore, affected by multiple vulnerabilities as referenced in the NXSA-AOS-7.6.0.6 advisory.

  - In an untrusted JMS environment, org.springframework.jms.support.converter.MappingJackson2MessageConverter     and org.springframework.jms.support.converter.JacksonJsonMessageConverter allow arbitrary class     instantiation, which can lead to unauthorized actions via gadget class deserialization. Affected versions:
    Spring Framework 7.0.0 through 7.0.7; 6.2.0 through 6.2.18; 6.1.0 through 6.1.27; 5.3.0 through 5.3.48.
    (CVE-2026-41855)

  - Postfix before 3.8.16, 3.9 before 3.9.10, and 3.10 before 3.10.9 sometimes allows a buffer over-read and     process crash via an enhanced status code that lacks text after the third number. (CVE-2026-43964)

  - Improper encoding of non-finite floating-point values during MapMessage JSON serialization in Apache Log4j     API produces output that is not valid JSON. This issue affects Apache Log4j API versions 2.13.1 through     2.25.4 and version 2.26.0. The fix for CVE-2026-34481 did not cover all code paths: when a MapMessage     contains a non-finite IEEE 754 value (NaN, Infinity, or -Infinity), MapMessage.asJson() emits the     corresponding bare token. RFC 8259 does not permit these tokens, so a conformant parser rejects the     resulting document. The defect is reachable only when both of the following conditions hold: * The     application uses the message resolver https://logging.apache.org/log4j/2.x/manual/json-template-     layout.html#event-template-resolver-message of JsonTemplateLayout or any other layout that relies on     MapMessage.asJson() or MapMessage.getFormattedMessage(new String[]{JSON}). * The application logs a     MapMessage that contains an attacker-controlled floating-point value. An attacker who can supply a non-     finite value can cause the affected layout to emit malformed JSON, which may corrupt the enclosing log     record or disrupt downstream log ingestion and parsing. Users are advised to upgrade to Apache Log4j API     2.25.5 or 2.26.1, both of which emit RFC 8259-compliant JSON for non-finite values. (CVE-2026-49844)

  - An authentication bypass vulnerability exists in the OAuth2 TokenIntrospectionService in Apache CXF. Due     to a missing 'throw' keyword in the security context check, the introspection endpoint     (/services/oauth2/introspect) can be accessed by any unauthenticated network attacker. However note that     this is a safeguard only in the case that someone forgot to enable authentication on the service. Users     are recommended to upgrade to version 4.2.2 or 4.1.7 or 3.6.12, which fixes this issue. (CVE-2026-50623)

  - The 'clientId' parameter from incoming HTTP requests is directly concatenated into OAuth2 server log     warning messages without sanitizing control characters. This allows an attacker to inject arbitrary     content, including fake log entries, into the server's log files. Users are recommended to upgrade to     versions 4.2.2 or 4.1.7 or 3.6.12, which fixes this issue. (CVE-2026-50629)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The Unity Linux 20 host has a package installed that is affected by a vulnerability as referenced in the UTSA-2026-099531 advisory.

    Improper encoding of non-finite floating-point values during MapMessage JSON serialization in Apache Log4j     API produces output that is not valid JSON. This issue affects Apache Log4j API versions 2.13.1 through     2.25.4 and version 2.26.0.

    The fix for CVE-2026-34481 did not cover all code paths: when a MapMessage contains a non-finite IEEE 754     value (NaN, Infinity, or -Infinity), MapMessage.asJson() emits the corresponding bare token. RFC 8259 does     not permit these tokens, so a conformant parser rejects the resulting document.

    The defect is reachable only when both of the following conditions hold:

      *  The application uses the  message resolver https://logging.apache.org/log4j/2.x/manual/json-template-     layout.html#event-template-resolver-message  of JsonTemplateLayout or any other layout that relies on     MapMessage.asJson() or MapMessage.getFormattedMessage(new String[]{JSON}).
      *  The application logs a MapMessage that contains an attacker-controlled floating-point value.


    An attacker who can supply a non-finite value can cause the affected layout to emit malformed JSON, which     may corrupt the enclosing log record or disrupt downstream log ingestion and parsing.

    Users are advised to upgrade to Apache Log4j API 2.25.5 or 2.26.1, both of which emit RFC 8259-compliant     JSON for non-finite values.

Tenable has extracted the preceding description block directly from the Unity Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The version of Apache Log4j on the remote host is affected by a vulnerability:

  - Improper encoding of non-finite floating-point values during MapMessage JSON serialization in Apache Log4j     API produces output that is not valid JSON. When a MapMessage contains a non-finite IEEE 754 value (NaN,     Infinity, or -Infinity), MapMessage.asJson() emits the corresponding bare token. RFC 8259 does not permit     these tokens, so a conformant parser rejects the resulting document. An attacker who can supply a non-finite     value can cause the affected layout to emit malformed JSON, which may corrupt the enclosing log record or     disrupt downstream log ingestion and parsing. (CVE-2026-49844)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - Improper encoding of non-finite floating-point values during MapMessage JSON serialization in Apache Log4j     API produces output that is not valid JSON. This issue affects Apache Log4j API versions 2.13.1 through     2.25.4 and version 2.26.0. The fix for CVE-2026-34481 did not cover all code paths: when a MapMessage     contains a non-finite IEEE 754 value (NaN, Infinity, or -Infinity), MapMessage.asJson() emits the     corresponding bare token. RFC 8259 does not permit these tokens, so a conformant parser rejects the     resulting document. The defect is reachable only when both of the following conditions hold: * The     application uses the message resolver https://logging.apache.org/log4j/2.x/manual/json-template-     layout.html#event-template-resolver-message of JsonTemplateLayout or any other layout that relies on     MapMessage.asJson() or MapMessage.getFormattedMessage(new String[]{JSON}). * The application logs a     MapMessage that contains an attacker-controlled floating-point value. An attacker who can supply a non-     finite value can cause the affected layout to emit malformed JSON, which may corrupt the enclosing log     record or disrupt downstream log ingestion and parsing. Users are advised to upgrade to Apache Log4j API     2.25.5 or 2.26.1, both of which emit RFC 8259-compliant JSON for non-finite values. (CVE-2026-49844)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Type	Severity
457733	Echo: org.apache.logging.log4j:log4j-api: security update to 2.25.5	Tenable Cloud Security	Echo Local Security Checks	Local	medium
457733	Echo: org.apache.logging.log4j:log4j-api: security update to 2.25.5	Tenable Self-Hosted Container Security	Echo Local Security Checks	Local	medium
360408	AlmaLinux 9.6 [TuxCare] Security Update: log4j / log4j-jcl / log4j-slf4j / log4j-web (ALMALINUX9.6:CLSA-2026:1784624635)	Nessus	Alma Linux Local Security Checks	Local	medium
360099	Rocky Linux 9.6 [TuxCare] Security Update: log4j / log4j-jcl / log4j-slf4j / log4j-web (ALMALINUX9.6:CLSA-2026:1784624635)	Nessus	Rocky Linux Local Security Checks	Local	medium
352321	AlmaLinux 9.2 [TuxCare] Security Update: log4j / log4j-jcl / log4j-slf4j / log4j-web (ALMALINUX9.2:CLSA-2026:1787235852)	Nessus	Alma Linux Local Security Checks	Local	medium
347981	Oracle Enterprise Manager Cloud Control (September 2026 CSPU)	Nessus	Misc.	Local	medium
341836	Amazon Linux 2023 : log4j, log4j-jcl, log4j-slf4j (ALAS2023-2026-2072)	Nessus	Amazon Linux Local Security Checks	Local	medium
341612	Nutanix AOS : Multiple Vulnerabilities (NXSA-AOS-7.6.0.6)	Nessus	Misc.	Local	high
336926	Unity Linux 20.1070e Security Update: log4j (UTSA-2026-099531)	Nessus	Unity Linux Local Security Checks	Local	medium
445957	SCA: security update for org.apache.logging.log4j:log4j-api (GHSA-qv9r-c865-cp47)	Tenable Cloud Security	SCA Checks	Local	medium
445957	SCA: security update for org.apache.logging.log4j:log4j-api (GHSA-qv9r-c865-cp47)	Tenable Self-Hosted Container Security	SCA Checks	Local	medium
327598	Apache Log4j 2.13.1 < 2.25.5 / 2.26.0 < 2.26.1 Improper JSON Serialization (CVE-2026-49844)	Nessus	Misc.	Local	medium
326435	Linux Distros Unpatched Vulnerability : CVE-2026-49844	Nessus	Misc.	Local	medium

Detections

Analytics

CVE-2026-49844

medium

Tenable Plugins

medium

medium

medium

medium

medium

medium

medium

high

medium

medium

medium

medium

medium