Skip to main content
VulnerabilityPublished Updated

CVE-2025-26696: Mozilla Thunderbird · CWE-290

Affects Mozilla ThunderbirdSource CVE Database V5

0

Not known to be exploited · CVSS 7.0 High : upgrade to 136 or 128.8 soon.

Data as of 26 Oct 2026, 10:12 UTC

CVSS 3.1 base score
7.0High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.3% chance of exploitation in 30 days – higher than 29% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 136, 128.8
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:L

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 10 Mar 2025

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq 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 26 Oct 2026.

What to do

Upgrade Mozilla Thunderbird to 136 or 128.8.

Affected software

ProductAffectedFixed in
Mozilla ThunderbirdAffected
  • <128.8
  • <136
Fixed in
  • 128.8
  • 136

AI-suggested

This vulnerability has been fixed in Mozilla Thunderbird versions 136 and ESR 128.8. Users and administrators should upgrade to these versions or later to remediate the issue. The vendor advisories explicitly confirm the availability of these fixes. No additional mitigation steps are required beyond applying the official updates. Since scripting is disabled when reading mail, exploitation through email is limited. Verify that Thunderbird installations are updated to at least version 136 or 128.8 ESR to ensure protection.

Description

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.

References

Community reviews

Loading reviews…