Linux Distros Unpatched Vulnerability : CVE-2026-34478

medium Nessus Plugin ID 306185

Synopsis

The Linux/Unix host has one or more packages installed with a vulnerability that the vendor indicates will not be patched.

Description

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

- Apache Log4j Core's Rfc5424Layout https://logging.apache.org/log4j/2.x/manual/layouts.html#RFC5424Layout , in versions 2.21.0 through 2.25.3, is vulnerable to log injection via CRLF sequences due to undocumented renames of security-relevant configuration attributes. Two distinct issues affect users of stream-based syslog services who configure Rfc5424Layout directly: * The newLineEscape attribute was silently renamed, causing newline escaping to stop working for users of TCP framing (RFC 6587), exposing them to CRLF injection in log output. * The useTlsMessageFormat attribute was silently renamed, causing users of TLS framing (RFC 5425) to be silently downgraded to unframed TCP (RFC 6587), without newline escaping. Users of the SyslogAppender are not affected, as its configuration attributes were not modified. Users are advised to upgrade to Apache Log4j Core 2.25.4, which corrects this issue. (CVE-2026-34478)

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

Solution

There is no known solution at this time.

Plugin Details

Severity: Medium

ID: 306185

File Name: unpatched_CVE_2026_34478.nasl

Version: 1.1

Type: Local

Agent: unix

Family: Misc.

Published: 4/13/2026

Updated: 4/13/2026

Supported Sensors: Frictionless Assessment AWS, Frictionless Assessment Azure, Frictionless Assessment Agent, Nessus Agent, Agentless Assessment, Nessus

Risk Information

VPR

Risk Factor: Low

Score: 3.8

CVSS v2

Risk Factor: Medium

Base Score: 6.4

Temporal Score: 5.4

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:N

CVSS Score Source: CVE-2026-34478

CVSS v3

Risk Factor: Critical

Base Score: 9.1

Temporal Score: 8.3

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Temporal Vector: CVSS:3.0/E:U/RL:U/RC:C

CVSS v4

Risk Factor: Medium

Base Score: 6.9

Threat Score: 2.7

Threat Vector: CVSS:4.0/E:U

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N

Vulnerability Information

CPE: p-cpe:/a:redhat:enterprise_linux:resteasy-javadoc, p-cpe:/a:redhat:enterprise_linux:pki-resteasy, p-cpe:/a:redhat:enterprise_linux:pki-resteasy-core, p-cpe:/a:redhat:enterprise_linux:pki-resteasy-servlet-initializer, p-cpe:/a:centos:centos:pki-resteasy, p-cpe:/a:centos:centos:pki-resteasy-core, p-cpe:/a:centos:centos:pki-resteasy-servlet-initializer, p-cpe:/a:centos:centos:log4j-slf4j, p-cpe:/a:redhat:enterprise_linux:log4j-slf4j, p-cpe:/a:centos:centos:resteasy-javadoc, cpe:/o:redhat:enterprise_linux:8, p-cpe:/a:redhat:enterprise_linux:log4j, p-cpe:/a:centos:centos:log4j, p-cpe:/a:redhat:enterprise_linux:resteasy, cpe:/o:centos:centos:8, p-cpe:/a:centos:centos:resteasy, cpe:/o:redhat:enterprise_linux:9, p-cpe:/a:redhat:enterprise_linux:pki-resteasy-client, p-cpe:/a:redhat:enterprise_linux:pki-resteasy-jackson2-provider, p-cpe:/a:centos:centos:pki-resteasy-client, p-cpe:/a:centos:centos:pki-resteasy-jackson2-provider, p-cpe:/a:centos:centos:log4j-jcl, p-cpe:/a:redhat:enterprise_linux:log4j-jcl, p-cpe:/a:centos:centos:log4j-web, p-cpe:/a:redhat:enterprise_linux:log4j-web

Required KB Items: Host/local_checks_enabled, Host/cpu, global_settings/vendor_unpatched, Host/OS/identifier

Exploit Ease: No known exploits are available

Vulnerability Publication Date: 4/10/2026

Reference Information

CVE: CVE-2026-34478

Detections

Analytics