Amazon Linux 2 : firefox, --advisory ALAS2FIREFOX-2026-056 (ALASFIREFOX-2026-056)

critical Nessus Plugin ID 306262

Synopsis

The remote Amazon Linux 2 host is missing a security update.

Description

The version of firefox installed on the remote host is prior to 140.9.0-1. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2FIREFOX-2026-056 advisory.

LIBPNG is a reference library for use in applications that read, create, and manipulate PNG (Portable Network Graphics) raster image files. In versions 1.2.1 through 1.6.55, `png_set_tRNS` and `png_set_PLTE` each alias a heap-allocated buffer between `png_struct` and `png_info`, sharing a single allocation across two structs with independent lifetimes. The `trans_alpha` aliasing has been present since at least libpng 1.0, and the `palette` aliasing since at least 1.2.1. Both affect all prior release lines `png_set_tRNS` sets `png_ptr->trans_alpha = info_ptr->trans_alpha` (256-byte buffer) and `png_set_PLTE` sets `info_ptr->palette = png_ptr->palette` (768-byte buffer). In both cases, calling `png_free_data` (with `PNG_FREE_TRNS` or `PNG_FREE_PLTE`) frees the buffer through `info_ptr` while the corresponding `png_ptr` pointer remains dangling. Subsequent row-transform functions dereference and, in some code paths, write to the freed memory. A second call to `png_set_tRNS` or `png_set_PLTE` has the same effect, because both functions call `png_free_data` internally before reallocating the `info_ptr` buffer. Version 1.6.56 fixes the issue.

NOTE: https://github.com/pnggroup/libpng/security/advisories/GHSA-m4pc-p4q3-4c7jNOTE:
https://github.com/pnggroup/libpng/pull/824NOTE: Fixed by:
https://github.com/pnggroup/libpng/commit/23019269764e35ed8458e517f1897bd3c54820eb (v1.6.56)NOTE: Fixed by: https://github.com/pnggroup/libpng/commit/a3a21443ed12bfa1ef46fa0d4fb2b74a0fa34a25 (v1.6.56)NOTE:
Fixed by: https://github.com/pnggroup/libpng/commit/7ea9eea884a2328cc7fdcb3c0c00246a50d90667 (v1.6.56)NOTE: Fixed by:
https://github.com/pnggroup/libpng/commit/c1b0318b393c90679e6fa5bc1d329fd5d5012ec1 (v1.6.56) (CVE-2026-33416)

LIBPNG is a reference library for use in applications that read, create, and manipulate PNG (Portable Network Graphics) raster image files. In versions 1.6.36 through 1.6.55, an out-of-bounds read and write exists in libpng's ARM/AArch64 Neon-optimized palette expansion path. When expanding 8-bit paletted rows to RGB or RGBA, the Neon loop processes a final partial chunk without verifying that enough input pixels remain. Because the implementation works backward from the end of the row, the final iteration dereferences pointers before the start of the row buffer (OOB read) and writes expanded pixel data to the same underflowed positions (OOB write). This is reachable via normal decoding of attacker-controlled PNG input if Neon is enabled. Version 1.6.56 fixes the issue.

NOTE: https://github.com/pnggroup/libpng/security/advisories/GHSA-wjr5-c57x-95m2NOTE: Introduced with:
https://github.com/pnggroup/libpng/commit/7734cda20cf1236aef60f3bbd2267c97bbb40869 (v1.6.36)NOTE: Fixed by: https://github.com/pnggroup/libpng/commit/aba9f18eba870d14fb52c5ba5d73451349e339c3 (v1.6.56) (CVE-2026-33636)

Race condition, use-after-free in the Graphics: WebRender component. This vulnerability affects Firefox < 149, Firefox ESR < 115.34, and Firefox ESR < 140.9. (CVE-2026-4684)

Incorrect boundary conditions in the Graphics: Canvas2D component. This vulnerability affects Firefox < 149, Firefox ESR < 115.34, and Firefox ESR < 140.9. (CVE-2026-4685)

Incorrect boundary conditions in the Graphics: Canvas2D component. This vulnerability affects Firefox < 149, Firefox ESR < 115.34, and Firefox ESR < 140.9. (CVE-2026-4686)

Sandbox escape due to incorrect boundary conditions in the Telemetry component. This vulnerability affects Firefox < 149, Firefox ESR < 115.34, and Firefox ESR < 140.9. (CVE-2026-4687)

Sandbox escape due to use-after-free in the Disability Access APIs component. This vulnerability affects Firefox < 149 and Firefox ESR < 140.9. (CVE-2026-4688)

Sandbox escape due to incorrect boundary conditions, integer overflow in the XPCOM component. This vulnerability affects Firefox < 149, Firefox ESR < 115.34, and Firefox ESR < 140.9. (CVE-2026-4689)

Sandbox escape due to incorrect boundary conditions, integer overflow in the XPCOM component. This vulnerability affects Firefox < 149, Firefox ESR < 115.34, and Firefox ESR < 140.9. (CVE-2026-4690)

Use-after-free in the CSS Parsing and Computation component. This vulnerability affects Firefox < 149, Firefox ESR < 115.34, and Firefox ESR < 140.9. (CVE-2026-4691)

Sandbox escape in the Responsive Design Mode component. This vulnerability affects Firefox < 149, Firefox ESR < 115.34, and Firefox ESR < 140.9. (CVE-2026-4692)

Incorrect boundary conditions in the Audio/Video: Playback component. This vulnerability affects Firefox < 149, Firefox ESR < 115.34, and Firefox ESR < 140.9. (CVE-2026-4693)

Incorrect boundary conditions, integer overflow in the Graphics component. This vulnerability affects Firefox < 149, Firefox ESR < 115.34, and Firefox ESR < 140.9. (CVE-2026-4694)

Incorrect boundary conditions in the Audio/Video: Web Codecs component. This vulnerability affects Firefox < 149 and Firefox ESR < 140.9. (CVE-2026-4695)

Use-after-free in the Layout: Text and Fonts component. This vulnerability affects Firefox < 149, Firefox ESR < 115.34, and Firefox ESR < 140.9. (CVE-2026-4696)

Incorrect boundary conditions in the Audio/Video: Web Codecs component. This vulnerability affects Firefox < 149 and Firefox ESR < 140.9. (CVE-2026-4697)

JIT miscompilation in the JavaScript Engine: JIT component. This vulnerability affects Firefox < 149, Firefox ESR < 115.34, and Firefox ESR < 140.9. (CVE-2026-4698)

Incorrect boundary conditions in the Layout: Text and Fonts component. This vulnerability affects Firefox < 149, Firefox ESR < 115.34, and Firefox ESR < 140.9. (CVE-2026-4699)

Mitigation bypass in the Networking: HTTP component. This vulnerability affects Firefox < 149 and Firefox ESR < 140.9. (CVE-2026-4700)

Use-after-free in the JavaScript Engine component. This vulnerability affects Firefox < 149 and Firefox ESR < 140.9. (CVE-2026-4701)

JIT miscompilation in the JavaScript Engine component. This vulnerability affects Firefox < 149 and Firefox ESR < 140.9. (CVE-2026-4702)

Denial-of-service in the WebRTC: Signaling component. This vulnerability affects Firefox < 149 and Firefox ESR < 140.9. (CVE-2026-4704)

Undefined behavior in the WebRTC: Signaling component. This vulnerability affects Firefox < 149 and Firefox ESR < 140.9. (CVE-2026-4705)

Incorrect boundary conditions in the Graphics: Canvas2D component. This vulnerability affects Firefox < 149, Firefox ESR < 115.34, and Firefox ESR < 140.9. (CVE-2026-4706)

Incorrect boundary conditions in the Graphics: Canvas2D component. This vulnerability affects Firefox < 149, Firefox ESR < 115.34, and Firefox ESR < 140.9. (CVE-2026-4707)

Incorrect boundary conditions in the Graphics component. This vulnerability affects Firefox < 149 and Firefox ESR < 140.9. (CVE-2026-4708)

Incorrect boundary conditions in the Audio/Video: GMP component. This vulnerability affects Firefox < 149, Firefox ESR < 115.34, and Firefox ESR < 140.9. (CVE-2026-4709)

Incorrect boundary conditions in the Audio/Video component. This vulnerability affects Firefox < 149 and Firefox ESR < 140.9. (CVE-2026-4710)

Use-after-free in the Widget: Cocoa component. This vulnerability affects Firefox < 149 and Firefox ESR < 140.9. (CVE-2026-4711)

Information disclosure in the Widget: Cocoa component. This vulnerability affects Firefox < 149 and Firefox ESR < 140.9. (CVE-2026-4712)

Incorrect boundary conditions in the Graphics component. This vulnerability affects Firefox < 149 and Firefox ESR < 140.9. (CVE-2026-4713)

Incorrect boundary conditions in the Audio/Video component. This vulnerability affects Firefox < 149 and Firefox ESR < 140.9. (CVE-2026-4714)

Uninitialized memory in the Graphics: Canvas2D component. This vulnerability affects Firefox < 149 and Firefox ESR < 140.9. (CVE-2026-4715)

Incorrect boundary conditions, uninitialized memory in the JavaScript Engine component. This vulnerability affects Firefox < 149 and Firefox ESR < 140.9. (CVE-2026-4716)

Privilege escalation in the Netmonitor component. This vulnerability affects Firefox < 149 and Firefox ESR < 140.9. (CVE-2026-4717)

Undefined behavior in the WebRTC: Signaling component. This vulnerability affects Firefox < 149 and Firefox ESR < 140.9. (CVE-2026-4718)

Incorrect boundary conditions in the Graphics: Text component. This vulnerability affects Firefox < 149 and Firefox ESR < 140.9. (CVE-2026-4719)

Memory safety bugs present in Firefox ESR 140.8, Thunderbird ESR 140.8, Firefox 148 and Thunderbird 148.
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 affects Firefox < 149 and Firefox ESR < 140.9. (CVE-2026-4720)

Memory safety bugs present in Firefox ESR 115.33, Firefox ESR 140.8, Thunderbird ESR 140.8, Firefox 148 and Thunderbird 148. 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 affects Firefox < 149, Firefox ESR < 115.34, and Firefox ESR < 140.9. (CVE-2026-4721)

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.

Solution

Run 'yum update firefox' or or 'yum update --advisory ALAS2FIREFOX-2026-056' to update your system.

Plugin Details

Severity: Critical

ID: 306262

File Name: al2_ALASFIREFOX-2026-056.nasl

Version: 1.1

Type: Local

Agent: unix

Family: Amazon Linux Local Security Checks

Published: 4/14/2026

Updated: 4/14/2026

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

Risk Information

VPR

Risk Factor: High

Score: 7.4

CVSS v2

Risk Factor: Critical

Base Score: 10

Temporal Score: 7.8

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

CVSS Score Source: CVE-2026-4717

CVSS v3

Risk Factor: Critical

Base Score: 10

Temporal Score: 9

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

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

CVSS Score Source: CVE-2026-4692

Vulnerability Information

CPE: p-cpe:/a:amazon:linux:firefox, cpe:/o:amazon:linux:2

Required KB Items: Host/local_checks_enabled, Host/AmazonLinux/release, Host/AmazonLinux/rpm-list

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 4/14/2026

Vulnerability Publication Date: 3/4/2026

Reference Information

CVE: CVE-2026-33416, CVE-2026-33636, CVE-2026-4684, CVE-2026-4685, CVE-2026-4686, CVE-2026-4687, CVE-2026-4688, CVE-2026-4689, CVE-2026-4690, CVE-2026-4691, CVE-2026-4692, CVE-2026-4693, CVE-2026-4694, CVE-2026-4695, CVE-2026-4696, CVE-2026-4697, CVE-2026-4698, CVE-2026-4699, CVE-2026-4700, CVE-2026-4701, CVE-2026-4702, CVE-2026-4704, CVE-2026-4705, CVE-2026-4706, CVE-2026-4707, CVE-2026-4708, CVE-2026-4709, CVE-2026-4710, CVE-2026-4711, CVE-2026-4712, CVE-2026-4713, CVE-2026-4714, CVE-2026-4715, CVE-2026-4716, CVE-2026-4717, CVE-2026-4718, CVE-2026-4719, CVE-2026-4720, CVE-2026-4721

IAVA: 2026-A-0274-S

Detections

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