Vulnerability in Mozilla Thunderbird
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 was fixed in Thunderbird 136 and Thunderbird 128.8.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.0 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:L.
EPSS exploit prediction
EPSS: 0.003 (25.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 26th percentile — 25.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: +0.000
Affected products
- Mozilla Thunderbird — versions 128.8, 136
Weakness classification (CWE)
Public proof-of-concept exploits
References
- bugzilla.mozilla.org/show_bug.cgi (Issue Tracking)
- www.mozilla.org/security/advisories/mfsa2025-17/ (Vendor Advisory)
- www.mozilla.org/security/advisories/mfsa2025-18/ (Vendor Advisory)
Frequently asked questions
- What is CVE-2025-26696?
- CVE-2025-26696 is a high-severity vulnerability in Mozilla Thunderbird, classified under Authentication Bypass by Spoofing. CVSS score: 7.0/10. Published 2025-03-10.
- How severe is CVE-2025-26696?
- High severity. CVSS v3 base score is 7.0 out of 10.
- Is CVE-2025-26696 known to be exploited?
- 3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.