Double Free in Mozilla Thunderbird
CVE-2025-5262
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.
Vulnerability class: Double Free
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.004 (36.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 37th percentile — 36.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000
Affected products
- Mozilla Thunderbird — versions unspecified
Weakness classification (CWE)
References
- bugzilla.mozilla.org/show_bug.cgi (Permissions Required, Issue Tracking)
- www.mozilla.org/security/advisories/mfsa2025-45/ (Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2025-46/ (Vendor Advisory)
Frequently asked questions
- What is CVE-2025-5262?
- CVE-2025-5262 is a high-severity vulnerability in Mozilla Thunderbird, classified under Double Free. CVSS score: 7.5/10. Published 2025-05-27.
- How severe is CVE-2025-5262?
- High severity. CVSS v3 base score is 7.5 out of 10.