In libexpat before 2.8.1, the computational complexity of attribute name collision checks allows a denial of service via moderately sized crafted XML input.

The remote AlmaLinux 9 host has packages installed that are affected by a vulnerability as referenced in the ALSA-2026:23230 advisory.

    * libexpat: denial of service via crafted XML input (CVE-2026-45186)

Tenable has extracted the preceding description block directly from the AlmaLinux 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 remote Redhat Enterprise Linux 9 host has packages installed that are affected by a vulnerability as referenced in the RHSA-2026:23230 advisory.

    Expat is a C library for parsing XML documents.

    Security Fix(es):

    * libexpat: denial of service via crafted XML input (CVE-2026-45186)

    For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and     other related information, refer to the CVE page(s) listed in the References section.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise 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 remote Redhat Enterprise Linux 8 host has packages installed that are affected by a vulnerability as referenced in the RHSA-2026:22721 advisory.

    Expat is a C library for parsing XML documents.

    Security Fix(es):

    * libexpat: denial of service via crafted XML input (CVE-2026-45186)

    For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and     other related information, refer to the CVE page(s) listed in the References section.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise 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 remote Redhat Enterprise Linux 10 host has packages installed that are affected by a vulnerability as referenced in the RHSA-2026:22715 advisory.

    Expat is a C library for parsing XML documents.

    Security Fix(es):

    * libexpat: denial of service via crafted XML input (CVE-2026-45186)

    For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and     other related information, refer to the CVE page(s) listed in the References section.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise 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 remote RockyLinux 10 host has packages installed that are affected by a vulnerability as referenced in the RLSA-2026:22715 advisory.

    * libexpat: denial of service via crafted XML input (CVE-2026-45186)

Tenable has extracted the preceding description block directly from the RockyLinux 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 remote RockyLinux 9 host has packages installed that are affected by a vulnerability as referenced in the RLSA-2026:23230 advisory.

    * libexpat: denial of service via crafted XML input (CVE-2026-45186)

Tenable has extracted the preceding description block directly from the RockyLinux 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 remote RockyLinux 8 host has packages installed that are affected by a vulnerability as referenced in the RLSA-2026:22721 advisory.

    * libexpat: denial of service via crafted XML input (CVE-2026-45186)

Tenable has extracted the preceding description block directly from the RockyLinux 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 remote MiracleLinux 8 host has packages installed that are affected by a vulnerability as referenced in the AXSA:2026-758:06 advisory.

    * libexpat: denial of service via crafted XML input (CVE-2026-45186)

Tenable has extracted the preceding description block directly from the MiracleLinux 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 remote AlmaLinux 10 host has packages installed that are affected by a vulnerability as referenced in the ALSA-2026:22715 advisory.

    * libexpat: denial of service via crafted XML input (CVE-2026-45186)

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

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

An update of the expat package has been released.

The remote Oracle Linux 8 host has packages installed that are affected by a vulnerability as referenced in the ELSA-2026-22721 advisory.

    - Fix CVE-2026-45186

Tenable has extracted the preceding description block directly from the Oracle 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 remote AlmaLinux 8 host has packages installed that are affected by a vulnerability as referenced in the ALSA-2026:22721 advisory.

    * libexpat: denial of service via crafted XML input (CVE-2026-45186)

Tenable has extracted the preceding description block directly from the AlmaLinux 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 IBM HTTP Server running on the remote host is affected by multiple vulnerabilities:

  - IBM HTTP Server is vulnerable to denial of service and a potential remote code execution due to improper     input validation. (CVE-2026-9170)

  - IBM HTTP Server is vulnerable to remote code execution and denial of service in configurations with TLS     mutual authentication (client authentication). (CVE-2026-8855)

  - IBM HTTP Server contains a buffer overflow vulnerability. A privileged user, authenticated to the     Administration Server, could exploit this vulnerability to execute remote code or cause a denial of     service. (CVE-2026-8834)

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

The version of thunderbird installed on the remote host is prior to 140.10.2-1. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2-2026-3315 advisory.

    In libexpat before 2.8.1, the computational complexity of attribute name collision checks allows a denial     of service via moderately sized crafted XML input. (CVE-2026-45186)

    Use-after-free in the DOM: Networking component. This vulnerability was fixed in Firefox 150.0.2, Firefox     ESR 140.10.2, and Firefox ESR 115.35.2. (CVE-2026-8090)

    Incorrect boundary conditions in the Audio/Video: Playback component. This vulnerability was fixed in     Firefox 150, Thunderbird 150, Firefox ESR 140.10.1, Thunderbird 140.10.1, and Firefox ESR 115.35.2.
    (CVE-2026-8091)

    Memory safety bugs present in Firefox ESR 115.35.1, Firefox ESR 140.10.1 and Firefox 150.0.1. Some of     these bugs showed evidence of memory corruption and we presume that with enough effort some of these could     have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 150.0.2, Firefox ESR     140.10.2, and Firefox ESR 115.35.2. (CVE-2026-8092)

    Other issue in the WebRTC component. This vulnerability was fixed in Firefox ESR 140.10.2. (CVE-2026-8094)

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

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

The version of firefox installed on the remote host is prior to 140.10.2-1. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2FIREFOX-2026-060 advisory.

    In libexpat before 2.8.1, the computational complexity of attribute name collision checks allows a denial     of service via moderately sized crafted XML input. (CVE-2026-45186)

    Use-after-free in the DOM: Networking component. This vulnerability was fixed in Firefox 150.0.2, Firefox     ESR 140.10.2, and Firefox ESR 115.35.2. (CVE-2026-8090)

    Incorrect boundary conditions in the Audio/Video: Playback component. This vulnerability was fixed in     Firefox 150, Thunderbird 150, Firefox ESR 140.10.1, Thunderbird 140.10.1, and Firefox ESR 115.35.2.
    (CVE-2026-8091)

    Memory safety bugs present in Firefox ESR 115.35.1, Firefox ESR 140.10.1 and Firefox 150.0.1. Some of     these bugs showed evidence of memory corruption and we presume that with enough effort some of these could     have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 150.0.2, Firefox ESR     140.10.2, and Firefox ESR 115.35.2. (CVE-2026-8092)

    Other issue in the WebRTC component. This vulnerability was fixed in Firefox ESR 140.10.2. (CVE-2026-8094)

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

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 multiple vulnerabilities as referenced in the ALAS2023-2026-1725 advisory.

    In libexpat before 2.8.1, the computational complexity of attribute name collision checks allows a denial     of service via moderately sized crafted XML input. (CVE-2026-45186)

    Use-after-free in the DOM: Networking component. This vulnerability was fixed in Firefox 150.0.2, Firefox     ESR 140.10.2, and Firefox ESR 115.35.2. (CVE-2026-8090)

    Incorrect boundary conditions in the Audio/Video: Playback component. This vulnerability was fixed in     Firefox 150, Thunderbird 150, Firefox ESR 140.10.1, Thunderbird 140.10.1, and Firefox ESR 115.35.2.
    (CVE-2026-8091)

    Memory safety bugs present in Firefox ESR 115.35.1, Firefox ESR 140.10.1 and Firefox 150.0.1. Some of     these bugs showed evidence of memory corruption and we presume that with enough effort some of these could     have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 150.0.2, Firefox ESR     140.10.2, and Firefox ESR 115.35.2. (CVE-2026-8092)

    Other issue in the WebRTC component. This vulnerability was fixed in Firefox ESR 140.10.2. (CVE-2026-8094)

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

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

The version of expat installed on the remote host is prior to 2.7.5 / 2.8.1. It is, therefore, affected by a vulnerability as referenced in the SSA:2026-132-01 advisory.

    New expat packages are available for Slackware 15.0 and -current to fix a security issue.

Tenable has extracted the preceding description block directly from the expat 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 FreeBSD installed on the remote host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the bacc1417-4d82-11f1-87f3-18dbf25a98c6 advisory.

    Expat 2.8.1 was released yesterday. The key motivation for cutting a release and doing so now was:
    Fixing vulnerability CVE-2026-45186 that allows easy denial of service.
    See also https://github.com/libexpat/libexpat/pull/1216

Tenable has extracted the preceding description block directly from the FreeBSD 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 Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - In libexpat before 2.8.1, the computational complexity of attribute name collision checks allows a denial     of service via moderately sized crafted XML input. (CVE-2026-45186)

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

ID	Name	Product	Family	Severity
320647	AlmaLinux 9 : expat (ALSA-2026:23230)	Nessus	Alma Linux Local Security Checks	high
319589	RHEL 9 : expat (RHSA-2026:23230)	Nessus	Red Hat Local Security Checks	high
319564	RHEL 8 : expat (RHSA-2026:22721)	Nessus	Red Hat Local Security Checks	high
319550	RHEL 10 : expat (RHSA-2026:22715)	Nessus	Red Hat Local Security Checks	high
318830	RockyLinux 10 : expat (RLSA-2026:22715)	Nessus	Rocky Linux Local Security Checks	high
318814	RockyLinux 9 : expat (RLSA-2026:23230)	Nessus	Rocky Linux Local Security Checks	high
318754	RockyLinux 8 : expat (RLSA-2026:22721)	Nessus	Rocky Linux Local Security Checks	high
318739	MiracleLinux 8 : expat-2.5.0-2.el8_10 (AXSA:2026-758:06)	Nessus	Miracle Linux Local Security Checks	high
318616	AlmaLinux 10 : expat (ALSA-2026:22715)	Nessus	Alma Linux Local Security Checks	high
318605	Photon OS 5.0: Expat PHSA-2026-5.0-0862	Nessus	PhotonOS Local Security Checks	high
318590	Oracle Linux 8 : expat (ELSA-2026-22721)	Nessus	Oracle Linux Local Security Checks	high
318392	AlmaLinux 8 : expat (ALSA-2026:22721)	Nessus	Alma Linux Local Security Checks	high
317395	IBM HTTP Server 8.5.0.0 < 8.5.5.30 / 9.0.0.0 < 9.0.5.29 Multiple Vulnerabilities (7274065)	Nessus	Web Servers	critical
316912	Amazon Linux 2 : thunderbird, --advisory ALAS2-2026-3315 (ALAS-2026-3315)	Nessus	Amazon Linux Local Security Checks	high
316908	Amazon Linux 2 : firefox, --advisory ALAS2FIREFOX-2026-060 (ALASFIREFOX-2026-060)	Nessus	Amazon Linux Local Security Checks	high
316905	Amazon Linux 2023 : firefox (ALAS2023-2026-1725)	Nessus	Amazon Linux Local Security Checks	high
315994	Photon OS 4.0: Expat PHSA-2026-4.0-1022	Nessus	PhotonOS Local Security Checks	high
314368	Slackware Linux 15.0 / current expat Vulnerability (SSA:2026-132-01)	Nessus	Slackware Local Security Checks	high
314367	FreeBSD : Vulnerability found in Expat (bacc1417-4d82-11f1-87f3-18dbf25a98c6)	Nessus	FreeBSD Local Security Checks	high
313709	Linux Distros Unpatched Vulnerability : CVE-2026-45186	Nessus	Misc.	high

Detections

Analytics

CVE-2026-45186

high

Tenable Plugins

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critical

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