CVE-2025-26696
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedCertain 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceThunderbird incorrectly displayed certain crafted MIME email messages as containing encrypted OpenPGP messages when they actually only contained OpenPGP signed messages. This created a security UI spoofing issue where users believed messages were encrypted when they were not.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data< 128.8.0>= 129.0, < 136.0CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- High
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- Low
- Availability
- Low
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:L
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
-
Confirm Thunderbird is installedCheck for Thunderbird executable on Windows (C:\Program Files\Mozilla Thunderbird\thunderbird.exe), macOS (/Applications/Thunderbird.app), or Linux (which thunderbird). On Windows, also check Registry: HKEY_LOCAL_MACHINE\SOFTWARE\Mozilla\Thunderbird or HKEY_CURRENT_USER\SOFTWARE\Mozilla\Thunderbird for InstallPath value.Affected if Thunderbird is found on the system
-
Determine installed Thunderbird versionOn Windows: Run thunderbird.exe --version from the install directory, or right-click thunderbird.exe > Properties > Details > File version. On macOS: Right-click Thunderbird.app > Get Info > Version. On Linux: Run thunderbird --version in terminal.Affected if A version number is returned
-
Compare version against affected rangesMatch the installed version number to the affected ranges: versions < 128.8.0 OR versions >= 129.0 and < 136.0 are vulnerable. Versions 136.0 and later, and versions 128.8.0 through 129.0 (if any existed), are not affected.Affected if Installed version falls within < 128.8.0 or >= 129.0 and < 136.0
A user is affected if Thunderbird is installed and the version is less than 128.8.0, or greater than or equal to 129.0 but less than 136.0.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped128.8.0136.0
Update Thunderbird to version 136 or Thunderbird 128.8 or later to receive the fix for this vulnerability.
Thunderbird 136.0 (current release) or Thunderbird 128.8.0 (ESR)
- 1. Open Thunderbird and navigate to Help > About Thunderbird to check your current version
- 2. If you are on version 129.x or higher, upgrade to Thunderbird 136.0 or later
- 3. If you are on version 128.x, upgrade to Thunderbird 128.8.0 or later
- 4. Download the appropriate version from the official Mozilla Thunderbird download page: https://www.thunderbird.net/
- 5. Close Thunderbird completely before installing the update
- 6. Run the installer and follow the prompts to complete the upgrade
- 7. After installation, verify the version by checking Help > About Thunderbird shows 136.0+ or 128.8.0+
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation1.0 h
- Implementation2.0 h
- Testing1.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,424.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2025-26696 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2025-26696 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data