Debian dla-4526 : firefox-esr - security update

critical Nessus Plugin ID 307669

Synopsis

The remote Debian host is missing one or more security-related updates.

Description

The remote Debian 11 host has packages installed that are affected by multiple vulnerabilities as referenced in the dla-4526 advisory.

- ------------------------------------------------------------------------- Debian LTS Advisory DLA-4526-1 [email protected] https://www.debian.org/lts/security/ Emilio Pozuelo Monfort April 11, 2026 https://wiki.debian.org/LTS
- -------------------------------------------------------------------------

Package : firefox-esr Version : 140.9.1esr-1~deb11u1 CVE ID : CVE-2026-5731 CVE-2026-5732 CVE-2026-5734

Multiple security issues have been found in the Mozilla Firefox web browser, which could potentially result in the execution of arbitrary code.

For Debian 11 bullseye, these problems have been fixed in version 140.9.1esr-1~deb11u1.

We recommend that you upgrade your firefox-esr packages.

For the detailed security status of firefox-esr please refer to its security tracker page at:
https://security-tracker.debian.org/tracker/firefox-esr

Further information about Debian LTS security advisories, how to apply these updates to your system and frequently asked questions can be found at: https://wiki.debian.org/LTS

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

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

Solution

Upgrade the firefox-esr packages.

See Also

http://www.nessus.org/u?cd2c5e22

https://security-tracker.debian.org/tracker/CVE-2026-5731

https://security-tracker.debian.org/tracker/CVE-2026-5732

https://security-tracker.debian.org/tracker/CVE-2026-5734

https://packages.debian.org/source/bullseye/firefox-esr

Plugin Details

Severity: Critical

ID: 307669

File Name: debian_DLA-4526.nasl

Version: 1.1

Type: Local

Agent: unix

Published: 4/21/2026

Updated: 4/21/2026

Supported Sensors: Agentless Assessment, Continuous Assessment, Frictionless Assessment Agent, Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: High

Score: 7.4

CVSS v2

Risk Factor: Critical

Base Score: 10

Temporal Score: 7.4

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

CVSS Score Source: CVE-2026-5734

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Temporal Score: 8.5

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

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

Vulnerability Information

CPE: cpe:/o:debian:debian_linux:11.0, p-cpe:/a:debian:debian_linux:firefox-esr, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-ach, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-af, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-all, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-an, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-ar, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-ast, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-az, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-be, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-bg, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-br, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-bs, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-ca, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-cs, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-cy, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-da, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-de, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-dsb, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-el, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-en-gb, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-eo, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-es-ar, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-es-cl, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-es-es, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-es-mx, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-et, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-eu, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-fa, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-ff, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-fi, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-fr, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-fy-nl, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-ga-ie, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-gd, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-gl, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-gn, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-gu-in, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-he, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-hi-in, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-hr, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-hsb, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-hu, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-hy-am, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-id, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-is, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-it, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-ja, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-kk, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-km, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-kn, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-ko, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-lij, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-lt, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-lv, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-mk, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-mr, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-ms, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-nb-no, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-nl, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-nn-no, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-pa-in, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-pl, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-pt-br, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-pt-pt, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-rm, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-ro, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-ru, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-si, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-sk, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-sl, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-son, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-sq, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-sr, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-sv-se, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-ta, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-te, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-th, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-tr, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-uk, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-uz, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-vi, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-xh, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-zh-cn, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-zh-tw, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-cak, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-ka, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-kab, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-bn, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-ca-valencia, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-en-ca, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-ia, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-my, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-ne-np, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-oc, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-tl, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-trs, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-ur, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-sco, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-szl, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-fur, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-sc, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-tg, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-sat, p-cpe:/a:debian:debian_linux:firefox-esr-l10n-skr

Required KB Items: Host/local_checks_enabled, Host/Debian/release, Host/Debian/dpkg-l

Exploit Ease: No known exploits are available

Patch Publication Date: 4/11/2026

Vulnerability Publication Date: 4/7/2026

Reference Information

CVE: CVE-2026-5731, CVE-2026-5732, CVE-2026-5734