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TI-2026-04090 Aliases CVE-2026-4695GHSA-vxpv-c2h6-hq9v

Improper check for unusual conditions in Mozilla Firefox

Priority MEDIUM 40CWE-754Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
None · None · High
Fix status
Partial Red Hat: 17 fixed, 3 without a fix

Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat.

Summary

Incorrect boundary conditions in the Audio/Video: Web Codecs component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00714 53rd percentileScored 2026-11-07
Fix Partial Firefox (Mozilla): 140.9, 149Thunderbird (Mozilla): 140.9, 149Red Hat: 25 advisoriesRed Hat: 17 fixed, 3 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
MozillaFirefox—140.9, 149Patch availableCNA
MozillaThunderbird—140.9, 149Patch availableCNA
  • Firefox VendorMozilla Affected — Fixed in 140.9, 149 Patch available CNA
  • Thunderbird VendorMozilla Affected — Fixed in 140.9, 149 Patch available CNA

CPE configurations NVD · 2

CPEVersionsRoleVendor
cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*before 140.9.0VulnerableMozilla
cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*before 149.0VulnerableMozilla
  • cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:* Versions before 140.9.0 Vulnerable ·Mozilla
  • cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:* Versions before 149.0 Vulnerable ·Mozilla

Remediation

  • Fix · CNA Firefox (Mozilla) Fixed in 140.9, 149
  • Fix · CNA Thunderbird (Mozilla) Fixed in 140.9, 149

Red Hat 25 advisories

  • RHSA-2026:8850 Released 2026-04-20 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream AUS (v.8.4) thunderbird-140.9.0-1.el8_4
    • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) thunderbird-140.9.0-1.el8_4
  • RHSA-2026:8427 Released 2026-04-16 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux Server (v. 7 ELS) firefox-140.9.0-1.el7_9
  • RHSA-2026:8315 Released 2026-04-15 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream EUS (v. 10.0) thunderbird-140.9.0-1.el10_0
Show 22 more Red Hat advisories
  • RHSA-2026:8290 Released 2026-04-15 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream EUS (v.9.4) thunderbird-140.9.0-1.el9_4
  • RHSA-2026:8284 Released 2026-04-15 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream EUS (v.9.6) thunderbird-140.9.0-1.el9_6
  • RHSA-2026:8289 Released 2026-04-15 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream AUS (v.8.6) thunderbird-140.9.0-1.el8_6
    • Red Hat Enterprise Linux AppStream E4S (v.8.6) thunderbird-140.9.0-1.el8_6
    • Red Hat Enterprise Linux AppStream TUS (v.8.6) thunderbird-140.9.0-1.el8_6
  • RHSA-2026:8286 Released 2026-04-15 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream E4S (v.9.0) thunderbird-140.9.0-1.el9_0
  • RHSA-2026:8287 Released 2026-04-15 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream E4S (v.9.2) thunderbird-140.9.0-1.el9_2
  • RHSA-2026:8288 Released 2026-04-15 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream E4S (v.8.8) thunderbird-140.9.0-1.el8_8
    • Red Hat Enterprise Linux AppStream TUS (v.8.8) thunderbird-140.9.0-1.el8_8
  • RHSA-2026:8285 Released 2026-04-15 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream AUS (v. 8.2) thunderbird-140.9.0-1.el8_2
  • RHSA-2026:7858 Released 2026-04-13 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream AUS (v.8.4) firefox-140.9.0-1.el8_4
    • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) firefox-140.9.0-1.el8_4
  • RHSA-2026:7837 Released 2026-04-13 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream EUS (v.9.6) firefox-140.9.0-1.el9_6, firefox-x11-140.9.0-1.el9_6
  • RHSA-2026:7845 Released 2026-04-13 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream EUS (v.9.4) firefox-140.9.0-1.el9_4, firefox-x11-140.9.0-1.el9_4
  • RHSA-2026:7838 Released 2026-04-13 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream E4S (v.8.8) firefox-140.9.0-1.el8_8
    • Red Hat Enterprise Linux AppStream TUS (v.8.8) firefox-140.9.0-1.el8_8
  • RHSA-2026:7843 Released 2026-04-13 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream EUS (v. 10.0) firefox-140.9.0-1.el10_0
  • RHSA-2026:7842 Released 2026-04-13 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream AUS (v.8.6) firefox-140.9.0-1.el8_6
    • Red Hat Enterprise Linux AppStream E4S (v.8.6) firefox-140.9.0-1.el8_6
    • Red Hat Enterprise Linux AppStream TUS (v.8.6) firefox-140.9.0-1.el8_6
  • RHSA-2026:7841 Released 2026-04-13 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream E4S (v.9.2) firefox-140.9.0-1.el9_2, firefox-x11-140.9.0-1.el9_2
  • RHSA-2026:7839 Released 2026-04-13 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream E4S (v.9.0) firefox-140.9.0-1.el9_0
  • RHSA-2026:7840 Released 2026-04-13 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream AUS (v. 8.2) firefox-140.9.0-1.el8_2
  • RHSA-2026:6917 Released 2026-04-07 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream (v. 8) thunderbird-140.9.0-1.el8_10
  • RHSA-2026:6342 Released 2026-04-01 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream (v. 10) thunderbird-140.9.0-1.el10_1
  • RHSA-2026:6188 Released 2026-03-30 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream (v. 9) thunderbird-140.9.0-1.el9_7
  • RHSA-2026:5932 Released 2026-03-26 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream (v. 8) firefox-140.9.0-1.el8_10
  • RHSA-2026:5930 Released 2026-03-26 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream (v. 9) firefox-140.9.0-1.el9_7, firefox-x11-140.9.0-1.el9_7
  • RHSA-2026:5931 Released 2026-03-26 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream (v. 10) firefox-140.9.0-1.el10_1

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 10AffectedNo fix yet
Red Hat Enterprise Linux 6AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 7AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux AppStream (v. 10)Fixed RHSA-2026:5931, RHSA-2026:6342
Red Hat Enterprise Linux AppStream (v. 8)Fixed RHSA-2026:5932, RHSA-2026:6917
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2026:5930, RHSA-2026:6188
Red Hat Enterprise Linux AppStream AUS (v. 8.2)Fixed RHSA-2026:7840, RHSA-2026:8285
Red Hat Enterprise Linux AppStream AUS (v.8.4)Fixed RHSA-2026:7858, RHSA-2026:8850
Red Hat Enterprise Linux AppStream AUS (v.8.6)Fixed RHSA-2026:7842, RHSA-2026:8289
Red Hat Enterprise Linux AppStream E4S (v.8.6)Fixed RHSA-2026:7842, RHSA-2026:8289
Red Hat Enterprise Linux AppStream E4S (v.8.8)Fixed RHSA-2026:7838, RHSA-2026:8288
Red Hat Enterprise Linux AppStream E4S (v.9.0)Fixed RHSA-2026:7839, RHSA-2026:8286
Red Hat Enterprise Linux AppStream E4S (v.9.2)Fixed RHSA-2026:7841, RHSA-2026:8287
Red Hat Enterprise Linux AppStream EUS (v. 10.0)Fixed RHSA-2026:7843, RHSA-2026:8315
Red Hat Enterprise Linux AppStream EUS (v.9.4)Fixed RHSA-2026:7845, RHSA-2026:8290
Red Hat Enterprise Linux AppStream EUS (v.9.6)Fixed RHSA-2026:7837, RHSA-2026:8284
Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)Fixed RHSA-2026:7858, RHSA-2026:8850
Red Hat Enterprise Linux AppStream TUS (v.8.6)Fixed RHSA-2026:7842, RHSA-2026:8289
Red Hat Enterprise Linux AppStream TUS (v.8.8)Fixed RHSA-2026:7838, RHSA-2026:8288
Red Hat Enterprise Linux Server (v. 7 ELS)Fixed RHSA-2026:8427

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-4695
  2. 2026-10-03 Alias added: GHSA-vxpv-c2h6-hq9v

References

Advisory 2

Other 3

  • TI-2024-08981 Use after free in Mozilla Firefox KEVCVSS 3.1CRITICAL 9.8
  • TI-2022-09832 Use after free in Mozilla Firefox KEVCVSS 3.1CRITICAL 9.6
  • TI-2019-08769 Improper input validation in Mozilla Firefox ESR KEVCVSS 3.1CRITICAL 10.0
  • TI-2010-03577 Mozilla Firefox 3.5.x through 3.5.14 and 3.6.x through 3.6.11, Thunderbird 3.1.6 before… KEVCVSS 3.1CRITICAL 9.8
  • TI-2023-04799 Out-of-bounds write in Google Chrome KEVCVSS 3.1HIGH 8.8
  • TI-2023-04477 Out-of-bounds write in Google Chrome KEVCVSS 3.1HIGH 8.8
See all 3444 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences