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TI-2026-71875 Aliases CVE-2026-109748GHSA-pmrg-jx35-2qp3

Use-after-free in Mozilla Firefox and Thunderbird WebAssembly

Priority LOW 24CWE-416Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Required
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
Low · Low · None
Fix status
Fixed

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

Summary

Mozilla Firefox and Thunderbird before 158 are affected. A use-after-free in the JavaScript WebAssembly component (CWE-416) lets the program use memory after it has been freed. A remote attacker without privileges can affect confidentiality and integrity if a user interacts with attacker-controlled content.

Written with Claude Haiku 5.5 from the sources below · 2026-11-05

Description from the CNA

Use-after-free in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 158 and Thunderbird 158.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00223 13th percentileScored 2026-11-07
Fix Fixed Firefox (Mozilla): 158Thunderbird (Mozilla): 158

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
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—158Patch availableCNA
MozillaThunderbird—158Patch availableCNA
  • Firefox VendorMozilla Affected — Fixed in 158 Patch available CNA
  • Thunderbird VendorMozilla Affected — Fixed in 158 Patch available CNA

CPE names Threatist (inferred) · 2

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*——Mozilla
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*——Mozilla
  • cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:* Versions — — ·Mozilla
  • cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:* Versions — — ·Mozilla

Remediation

Update Mozilla Firefox and Thunderbird to version 158. The sources list no other fixed versions or vendor advisories for these products.

Written with Claude Haiku 5.5 from the sources below · 2026-11-05

  • Fix · CNA Firefox (Mozilla) Fixed in 158
  • Fix · CNA Thunderbird (Mozilla) Fixed in 158

Vendor assessments

Red Hat

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

Not affected: 5 products
  • Red Hat Enterprise Linux 10
  • Red Hat Enterprise Linux 6
  • Red Hat Enterprise Linux 7
  • Red Hat Enterprise Linux 8
  • Red Hat Enterprise Linux 9

Timeline

  1. 2026-10-13 Threatist record created from CVE-2026-109748
  2. 2026-10-13 Alias added: GHSA-pmrg-jx35-2qp3
  3. 2026-10-13 Fix available: Mozilla/Thunderbird@158 · CNA
  4. 2026-10-13 1 new reference · CNA
  5. 2026-10-31 Affected versions changed · Red Hat
  6. 2026-10-31 CVSS score added · Red Hat
  7. 2026-11-03 Affected versions changed · Red Hat
  8. 2026-11-04 Affected versions changed · Red Hat
  9. 2026-11-04 Fix available: RHSA-2026:93443 · Red Hat
  10. 2026-11-04 Fix available: Red Hat Enterprise Linux AppStream (v. 9) · Red Hat
  11. 2026-11-05 Affected versions changed · Red Hat

References

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 4204 →

Sources

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