# CVE-2025-26695: Downloading of OpenPGP keys from WKD used incorrect padding

> A network observer could learn the length of requested email addresses due to incorrect padding in OpenPGP key downloads.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 10 Mar 2025
- **Updated:** 13 Apr 2026
- **Also known as:** DEBIAN-CVE-2025-26695, GHSA-29qq-gf32-fj2m, UBUNTU-CVE-2025-26695

## What is CVE-2025-26695?

CVE-2025-26695 is a medium-severity vulnerability in Mozilla Thunderbird, published on 10 Mar 2025. It can only be exploited from the same machine or local network, with no action from the victim.

### Official 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.

## Which versions are affected by CVE-2025-26695?

It affects 1 product.


Products: Mozilla Thunderbird.

## How do I fix CVE-2025-26695?

Upgrade to a fixed version.

## Is CVE-2025-26695 being exploited?

There is no known exploitation of CVE-2025-26695 in the wild and no public exploit code.

## Other vulnerabilities in Mozilla Thunderbird

- [CVE-2026-92238](https://insights.sbomify.com/CVE-2026-92238/): Ambiguous parsing of mail headers (critical 9.8)
- [CVE-2026-84637](https://insights.sbomify.com/CVE-2026-84637/): Calendar invitation attachments could launch local executables (critical 9.8)
- [CVE-2021-43529](https://insights.sbomify.com/CVE-2021-43529/): Memory corruption in Thunderbird (critical 9.8)
- [CVE-2019-11703](https://insights.sbomify.com/CVE-2019-11703/): Memory corruption in Thunderbird (critical 9.8)
- [CVE-2019-11704](https://insights.sbomify.com/CVE-2019-11704/): Memory corruption in Thunderbird (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-26695 and fix it if it is affected.

What it is: CVE-2025-26695 is a medium-severity vulnerability in Mozilla Thunderbird, published on 10 Mar 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-26695 in the wild and no public exploit code.

Affected product: Mozilla Thunderbird. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2025-26695/ (Markdown: https://insights.sbomify.com/CVE-2025-26695/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-26695
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-26695
- OSV: https://osv.dev/vulnerability/CVE-2025-26695

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-26695/
Summaries are generated and may contain mistakes; the official description above is the record.