CVE-2021-29948: Mozilla Thunderbird

Low severity, CVSS 2.5. EPSS: 0.3% chance of exploitation in the next 30 days.

Signatures are written to disk before and read during verification, which might be subject to a race condition when a malicious local process or user is replacing the file. This vulnerability affects Thunderbird < 78.10.

Affected products

• Mozilla Thunderbird: before 78.10 (fixed in 78.10)

Published 2021-06-24. Last modified 2026-06-17.