CVE-2025-26696

Certain crafted MIME email messages that claimed to contain an encrypted OpenPGP message, which instead contained an OpenPGP signed message, were wrongly shown as being encrypted. This vulnerability affects Thunderbird < 136 and Thunderbird < 128.8.

Weakness

This attack-focused weakness is caused by incorrectly implemented authentication schemes that are subject to spoofing attacks.

Affected Software

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/21.html
• https://cwe.mitre.org/data/definitions/22.html
• https://cwe.mitre.org/data/definitions/459.html
• https://cwe.mitre.org/data/definitions/461.html
• https://cwe.mitre.org/data/definitions/473.html
• https://cwe.mitre.org/data/definitions/476.html
• https://cwe.mitre.org/data/definitions/59.html
• https://cwe.mitre.org/data/definitions/60.html
• https://cwe.mitre.org/data/definitions/667.html
• https://cwe.mitre.org/data/definitions/94.html

References

• https://bugzilla.mozilla.org/show_bug.cgi?id=1864205
• https://www.mozilla.org/security/advisories/mfsa2025-17/
• https://www.mozilla.org/security/advisories/mfsa2025-18/