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TI-2026-64929 Aliases CVE-2026-100790GHSA-9q5w-qfph-c2x4

Use after free in Mozilla Firefox

Priority MEDIUM 40CWE-416Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Required
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Partial Red Hat: 14 fixed, 3 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 XSLT component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Thunderbird 140.17, Thunderbird 153.4, Firefox 157, Firefox ESR 115.42, and Firefox ESR 140.17.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00319 25th percentileScored 2026-11-07
Fix Partial Firefox (Mozilla): 115.42, 140.17, 153.4 +1Thunderbird (Mozilla): 140.17, 153.4, 157Red Hat: 21 advisoriesRed Hat: 14 fixed, 3 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
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—115.42, 140.17, 153.4, 157Patch availableCNA
MozillaThunderbird—140.17, 153.4, 157Patch availableCNA
  • Firefox VendorMozilla Affected — Fixed in 115.42, 140.17, 153.4, 157 Patch available CNA
  • Thunderbird VendorMozilla Affected — Fixed in 140.17, 153.4, 157 Patch available CNA

CPE configurations NVD · 2

CPEVersionsRoleVendor
cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*before 115.42.0; 116.0 to before 140.17.0; 141.0 to before 153.4.0; 154.0.0 to before 157.0.0VulnerableMozilla
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*before 140.17.0; 141.0 to before 153.4.0; 154.0 to before 157.0VulnerableMozilla
  • cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:* Versions before 115.42.0; 116.0 to before 140.17.0; 141.0 to before 153.4.0; 154.0.0 to before 157.0.0 Vulnerable ·Mozilla
  • cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:* Versions before 140.17.0; 141.0 to before 153.4.0; 154.0 to before 157.0 Vulnerable ·Mozilla

Remediation

  • Fix · CNA Firefox (Mozilla) Fixed in 115.42, 140.17, 153.4, 157
  • Fix · CNA Thunderbird (Mozilla) Fixed in 140.17, 153.4, 157

Red Hat 21 advisories

  • RHSA-2026:92363 Released 2026-11-02 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux Server (v. 7 ELS) firefox-140.17.0-1.el7_9
  • RHSA-2026:92226 Released 2026-10-29 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream E4S (v.9.2) firefox-140.17.0-1.el9_2, firefox-x11-140.17.0-1.el9_2
  • RHSA-2026:92227 Released 2026-10-29 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream EUS (v. 10.0) firefox-140.17.0-1.el10_0
Show 18 more Red Hat advisories
  • RHSA-2026:92228 Released 2026-10-29 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream AUS (v.8.6) firefox-140.17.0-1.el8_6
    • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6) firefox-140.17.0-1.el8_6
  • RHSA-2026:92335 Released 2026-10-29 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream EUS (v.9.6) firefox-140.17.0-1.el9_6, firefox-x11-140.17.0-1.el9_6
  • RHSA-2026:92327 Released 2026-10-29 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream E4S (v.8.8) firefox-140.17.0-1.el8_8
    • Red Hat Enterprise Linux AppStream TUS (v.8.8) firefox-140.17.0-1.el8_8
  • RHSA-2026:91633 Released 2026-10-28 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream E4S (v.8.8) thunderbird-140.17.0-1.el8_8
    • Red Hat Enterprise Linux AppStream TUS (v.8.8) thunderbird-140.17.0-1.el8_8
  • RHSA-2026:92012 Released 2026-10-28 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream E4S (v.9.4) firefox-140.17.0-1.el9_4, firefox-x11-140.17.0-1.el9_4
  • RHSA-2026:92011 Released 2026-10-28 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream AUS (v.8.4) firefox-140.17.0-1.el8_4
    • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) firefox-140.17.0-1.el8_4
  • RHSA-2026:91634 Released 2026-10-28 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream AUS (v.8.6) thunderbird-140.17.0-1.el8_6
    • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6) thunderbird-140.17.0-1.el8_6
  • RHSA-2026:90913 Released 2026-10-27 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream (v. 8) thunderbird-140.17.0-1.el8_10
  • RHSA-2026:85244 Released 2026-10-19 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream EUS (v.9.6) thunderbird-140.17.0-1.el9_6
  • RHSA-2026:85243 Released 2026-10-19 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream AUS (v.8.4) thunderbird-140.17.0-1.el8_4
    • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) thunderbird-140.17.0-1.el8_4
  • RHSA-2026:85241 Released 2026-10-19 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream E4S (v.9.4) thunderbird-140.17.0-1.el9_4
  • RHSA-2026:85242 Released 2026-10-19 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream E4S (v.9.2) thunderbird-140.17.0-1.el9_2
  • RHSA-2026:85240 Released 2026-10-19 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream EUS (v. 10.0) thunderbird-140.17.0-1.el10_0
  • RHSA-2026:80694 Released 2026-10-12 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream (v. 9) thunderbird-140.17.0-1.el9_8
  • RHSA-2026:80674 Released 2026-10-12 · Red Hat rating Important
    thunderbird security update
    • Red Hat Enterprise Linux AppStream (v. 10) thunderbird-140.17.0-1.el10_2
  • RHSA-2026:76761 Released 2026-10-08 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream (v. 9) firefox-140.17.0-1.el9_8, firefox-x11-140.17.0-1.el9_8
  • RHSA-2026:76764 Released 2026-10-06 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream (v. 10) firefox-140.17.0-1.el10_2
  • RHSA-2026:76850 Released 2026-10-06 · Red Hat rating Important
    firefox security update
    • Red Hat Enterprise Linux AppStream (v. 8) firefox-140.17.0-1.el8_10

Vendor assessments

Red Hat

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

ProductStatusPlan or fix
Red Hat Enterprise Linux 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-2026:76764, RHSA-2026:80674
Red Hat Enterprise Linux AppStream (v. 8)Fixed RHSA-2026:76850, RHSA-2026:90913
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2026:76761, RHSA-2026:80694
Red Hat Enterprise Linux AppStream AUS (v.8.4)Fixed RHSA-2026:85243, RHSA-2026:92011
Red Hat Enterprise Linux AppStream AUS (v.8.6)Fixed RHSA-2026:91634, RHSA-2026:92228
Red Hat Enterprise Linux AppStream E4S (v.8.8)Fixed RHSA-2026:91633, RHSA-2026:92327
Red Hat Enterprise Linux AppStream E4S (v.9.2)Fixed RHSA-2026:85242, RHSA-2026:92226
Red Hat Enterprise Linux AppStream E4S (v.9.4)Fixed RHSA-2026:85241, RHSA-2026:92012
Red Hat Enterprise Linux AppStream EUS (v. 10.0)Fixed RHSA-2026:85240, RHSA-2026:92227
Red Hat Enterprise Linux AppStream EUS (v.9.6)Fixed RHSA-2026:85244, RHSA-2026:92335
Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)Fixed RHSA-2026:85243, RHSA-2026:92011
Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6)Fixed RHSA-2026:91634, RHSA-2026:92228
Red Hat Enterprise Linux AppStream TUS (v.8.8)Fixed RHSA-2026:91633, RHSA-2026:92327
Red Hat Enterprise Linux Server (v. 7 ELS)Fixed RHSA-2026:92363
Not affected: 1 product
  • Red Hat Enterprise Linux 10

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-100790
  2. 2026-10-03 Alias added: GHSA-9q5w-qfph-c2x4
  3. 2026-10-16 Affected versions changed · Red Hat
  4. 2026-10-16 CVSS score added · Red Hat
  5. 2026-10-24 Fix available: RHSA-2026:76850 · Red Hat
  6. 2026-10-24 Fix available: RHSA-2026:76761 · Red Hat
  7. 2026-10-24 Fix available: RHSA-2026:76764 · Red Hat
  8. 2026-10-24 Fix available: RHSA-2026:80674 · Red Hat
  9. 2026-10-24 Fix available: RHSA-2026:80694 · Red Hat
  10. 2026-10-24 Fix available: RHSA-2026:85240 · Red Hat
  11. 2026-10-24 Fix available: RHSA-2026:85243 · Red Hat
  12. 2026-10-24 Fix available: RHSA-2026:85241 · Red Hat
  13. 2026-10-24 Fix available: RHSA-2026:85244 · Red Hat
  14. 2026-10-24 Fix available: RHSA-2026:85242 · Red Hat
  15. 2026-10-24 Fix available: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux AppStream (v. 8), Red Hat Enterprise Linux AppStream (v. 9) +6 · Red Hat
  16. 2026-10-28 Affected versions changed · Red Hat
  17. 2026-10-29 Fix available: RHSA-2026:90913 · Red Hat
  18. 2026-10-29 Fix available: RHSA-2026:92335 · Red Hat
  19. 2026-10-29 Fix available: RHSA-2026:92327 · Red Hat
  20. 2026-10-29 Fix available: Red Hat Enterprise Linux AppStream E4S (v.8.8), Red Hat Enterprise Linux AppStream TUS (v.8.8) · Red Hat
  21. 2026-10-30 Fix available: RHSA-2026:91634 · Red Hat
  22. 2026-10-30 Fix available: RHSA-2026:91633 · Red Hat
  23. 2026-10-30 Fix available: RHSA-2026:92012 · Red Hat
  24. 2026-10-30 Fix available: RHSA-2026:92011 · Red Hat
  25. 2026-10-30 Fix available: RHSA-2026:92227 · Red Hat
  26. 2026-10-30 Fix available: RHSA-2026:92226 · Red Hat
  27. 2026-10-30 Fix available: RHSA-2026:92228 · Red Hat
  28. 2026-10-30 Fix available: Red Hat Enterprise Linux AppStream AUS (v.8.6), Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6) · Red Hat
  29. 2026-11-02 Affected versions changed · Red Hat
  30. 2026-11-02 Fix available: Red Hat Enterprise Linux Server (v. 7 ELS) · Red Hat
  31. 2026-11-03 Fix available: RHSA-2026:92363 · Red Hat

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