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TI-2025-04726 Aliases CVE-2025-5262GHSA-v5j6-fjmw-w724

Double free in Mozilla Thunderbird

Priority LOW 39CWE-415Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA. Impact type from CWE-415 and the CVSS impact.

Summary

A double-free could have occurred in `vpx_codec_enc_init_multi` after a failed allocation when initializing the encoder for WebRTC. This could have caused memory corruption and a potentially exploitable crash. This vulnerability affects Thunderbird < 139 and Thunderbird < 128.11.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00464 40th percentileScored 2026-11-07
Fix Fixed Thunderbird (Mozilla): 139, 128.11

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
MozillaThunderbirdbefore 139139Patch availableCNA
MozillaThunderbirdbefore 128.11128.11Patch availableCNA
  • Thunderbird VendorMozilla Affected before 139 Fixed in 139 Patch available CNA
  • Thunderbird VendorMozilla Affected before 128.11 Fixed in 128.11 Patch available CNA

CPE configurations NVD · 2

CPEVersionsRoleVendor
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:esr:*:*:*before 128.11.0VulnerableMozilla
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:-:*:*:*before 139.0VulnerableMozilla
  • cpe:2.3:a:mozilla:thunderbird:*:*:*:*:esr:*:*:* Versions before 128.11.0 Vulnerable ·Mozilla
  • cpe:2.3:a:mozilla:thunderbird:*:*:*:*:-:*:*:* Versions before 139.0 Vulnerable ·Mozilla

Remediation

  • Fix · CNA Thunderbird (Mozilla) Fixed in 139
  • Fix · CNA Thunderbird (Mozilla) Fixed in 128.11

Timeline

  1. 2026-10-02 Threatist record created from CVE-2025-5262
  2. 2026-10-03 Alias added: GHSA-v5j6-fjmw-w724

References

Advisory 2

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 2067 →

Sources

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