Vulnerability · CVE-2025-5262
A double-free could have occurred in after a failed allocation when initializing the encoder for WebRTC.
Published May 27, 2025 · catalog updated Aug 25, 2025 · Mozilla Thunderbird
Check if you run it
No confirmed exploitation is on record for CVE-2025-5262. EPSS is 0.45%. Act only if a listed version of Mozilla Thunderbird is installed.
Gaps on this record
- No vendor fix or required action is stored. Compare the linked advisory before you change production.
- Severity
- High7.5
- Known exploitation
- Not in CISA/VulnCheck KEV
- EPSS
- 0.45%
- Remediation
- Version ranges on file
- Affected products
- vendor Mozilla Thunderbird unspecified <128.11
A double-free could have occurred in 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.
Are you affected?
Enter the version you run. The result uses only the ranges stored on this record.
The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.
- vendor Mozilla Thunderbird unspecified <128.11unspecified <128.11
How to fix CVE-2025-5262
Recommended remediation
Affected version ranges suggest a fixed boundary. Verify against the vendor advisory for your release.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
No confirmed exploitation is on record for CVE-2025-5262. EPSS is 0.45%. Act only if a listed version of Mozilla Thunderbird is installed.
Which versions are affected?
Compare what you have installed with Mozilla Thunderbird unspecified <128.11 unspecified <128.11. Compare the installed version with the linked vendor advisory before you change production.
What should an analyst verify?
No weakness class is stored. EPSS 0.45%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Code
The project this record applies to. Exploit listings stay in References.
No public source repository is identified for this product.
Timeline
Detection, updates, and resolution for this record.
May 27, 2025 · EUVD
Detected
A double-free could have occurred in 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.
Aug 25, 2025 · EUVD
Updated
A double-free could have occurred in 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.
Sources
- CVE.orgVulnerability recordCVE-2025-5262
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2025-5262
30-day exploitation probability 0.4%
first.org - EUVDVulnerability recordEUVD-2025-25234
A double-free could have occurred in 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.
euvd.enisa.europa.eu
References
Freshness
Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.