Read the docs
TI-2026-52645 Aliases CVE-2026-74943GHSA-cx5v-35ww-82cj

Use after free in Mozilla Firefox

Priority MEDIUM 51CWE-416Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Partial Red Hat: 14 fixed, 4 without a fix

Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat. Impact type from CWE-416 and the CVSS impact.

Summary

Use-after-free in the Graphics: ImageLib component. This vulnerability was fixed in Firefox 154, Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00961 61st percentileScored 2026-11-07
Fix Partial Firefox (Mozilla): 115.39, 140.14, 153.1 +1Thunderbird (Mozilla): 140.14, 153.1, 154Red Hat: 15 advisoriesRed Hat: 14 fixed, 4 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Total

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—115.39, 140.14, 153.1, 154Patch availableCNA
MozillaThunderbird—140.14, 153.1, 154Patch availableCNA
  • Firefox VendorMozilla Affected — Fixed in 115.39, 140.14, 153.1, 154 Patch available CNA
  • Thunderbird VendorMozilla Affected — Fixed in 140.14, 153.1, 154 Patch available CNA

CPE configurations NVD · 2

CPEVersionsRoleVendor
cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*before 115.39.0; 116.0 to before 140.14.0; 141.0 to before 153.1.0VulnerableMozilla
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*before 140.14.0; 141.0 to before 153.1.0VulnerableMozilla
  • cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:* Versions before 115.39.0; 116.0 to before 140.14.0; 141.0 to before 153.1.0 Vulnerable ·Mozilla
  • cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:* Versions before 140.14.0; 141.0 to before 153.1.0 Vulnerable ·Mozilla

Remediation

  • Fix · CNA Firefox (Mozilla) Fixed in 115.39, 140.14, 153.1, 154
  • Fix · CNA Thunderbird (Mozilla) Fixed in 140.14, 153.1, 154

Red Hat 15 advisories

  • RHSA-2026:65888 Released 2026-09-09 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream E4S (v.9.2) firefox-140.14.0-1.el9_2, firefox-x11-140.14.0-1.el9_2
  • RHSA-2026:65766 Released 2026-09-09 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream E4S (v.9.2) thunderbird-140.14.0-1.el9_2
  • RHSA-2026:65670 Released 2026-09-08 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream EUS (v.9.6) thunderbird-140.14.0-1.el9_6
Show 12 more Red Hat advisories
  • RHSA-2026:65669 Released 2026-09-08 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream E4S (v.9.4) thunderbird-140.14.0-1.el9_4
  • RHSA-2026:65442 Released 2026-09-08 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux Server (v. 7 ELS) firefox-140.14.0-1.el7_9
  • RHSA-2026:65158 Released 2026-09-08 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream (v. 9) thunderbird-140.14.0-1.el9_8
  • RHSA-2026:65103 Released 2026-09-08 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream EUS (v.9.6) firefox-140.14.0-1.el9_6, firefox-x11-140.14.0-1.el9_6
  • RHSA-2026:65105 Released 2026-09-08 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream E4S (v.9.4) firefox-140.14.0-1.el9_4, firefox-x11-140.14.0-1.el9_4
  • RHSA-2026:65111 Released 2026-09-08 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream AUS (v.8.4) firefox-140.14.0-1.el8_4
    • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) firefox-140.14.0-1.el8_4
  • RHSA-2026:65110 Released 2026-09-08 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream AUS (v.8.6) firefox-140.14.0-1.el8_6
    • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6) firefox-140.14.0-1.el8_6
  • RHSA-2026:64813 Released 2026-09-08 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream EUS (v. 10.0) firefox-140.14.0-1.el10_0
  • RHSA-2026:64814 Released 2026-09-08 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream E4S (v.8.8) firefox-140.14.0-1.el8_8
    • Red Hat Enterprise Linux AppStream TUS (v.8.8) firefox-140.14.0-1.el8_8
  • RHSA-2026:58897 Released 2026-08-24 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream (v. 9) firefox-140.14.0-1.el9_8, firefox-x11-140.14.0-1.el9_8
  • RHSA-2026:58899 Released 2026-08-24 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream (v. 10) firefox-140.14.0-1.el10_2
  • RHSA-2026:58898 Released 2026-08-24 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream (v. 8) firefox-140.14.0-1.el8_10

Vendor assessments

Red Hat

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

ProductStatusPlan or fix
Red Hat Enterprise Linux 10Affected—
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 8AffectedNo fix yet
Red Hat Enterprise Linux AppStream (v. 10)Fixed RHSA-2026:58899
Red Hat Enterprise Linux AppStream (v. 8)Fixed RHSA-2026:58898
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2026:58897, RHSA-2026:65158
Red Hat Enterprise Linux AppStream AUS (v.8.4)Fixed RHSA-2026:65111
Red Hat Enterprise Linux AppStream AUS (v.8.6)Fixed RHSA-2026:65110
Red Hat Enterprise Linux AppStream E4S (v.8.8)Fixed RHSA-2026:64814
Red Hat Enterprise Linux AppStream E4S (v.9.2)Fixed RHSA-2026:65766, RHSA-2026:65888
Red Hat Enterprise Linux AppStream E4S (v.9.4)Fixed RHSA-2026:65105, RHSA-2026:65669
Red Hat Enterprise Linux AppStream EUS (v. 10.0)Fixed RHSA-2026:64813
Red Hat Enterprise Linux AppStream EUS (v.9.6)Fixed RHSA-2026:65103, RHSA-2026:65670
Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)Fixed RHSA-2026:65111
Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6)Fixed RHSA-2026:65110
Red Hat Enterprise Linux AppStream TUS (v.8.8)Fixed RHSA-2026:64814
Red Hat Enterprise Linux Server (v. 7 ELS)Fixed RHSA-2026:65442

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-74943
  2. 2026-10-03 Alias added: GHSA-cx5v-35ww-82cj
  3. 2026-11-07 EPSS moved to the 50th–90th percentile

References

Advisory 7

Other 1

  • 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