CVE-2025-26695: Mozilla Thunderbird · Vulnerability
Affects Mozilla ThunderbirdSource CVE Database V5
Not known to be exploited · CVSS 5.3 Medium : upgrade to 128.8 when convenient.
Data as of 26 Oct 2026, 06:26 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 4% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 128.8
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:LExploitation evidence
Disclosed: evidence found.
CVE published 10 Mar 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-26.
What to do
Upgrade Mozilla Thunderbird to 128.8.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Mozilla Thunderbird | Affected
| Fixed in
|
AI-suggested
This vulnerability has been fixed in Mozilla Thunderbird versions 136 and 128.8 (ESR). Users and administrators should upgrade to these versions or later to remediate the issue. The vendor advisories from Mozilla confirm that the flaw is addressed in these releases. No additional mitigation steps are required beyond applying the official updates.
Description
When requesting an OpenPGP key from a WKD server, an incorrect padding size was used and a network observer could have learned the length of the requested email address. This vulnerability was fixed in Thunderbird 136 and Thunderbird 128.8.