# CVE-2025-2866: PDF signature forgery with adbe.pkcs7.sha1 SubFilter

> Attackers can forge PDF signatures in LibreOffice by exploiting improper validation of adbe.pkcs7.sha1 signatures, bypassing integrity checks.

- **Severity:** Low 2.4 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:P/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 27 Apr 2025
- **Updated:** 3 Nov 2025
- **Also known as:** BELL-CVE-2025-2866, DEBIAN-CVE-2025-2866, DSA-5908-1, GHSA-22mj-r7hq-f9h2, MGASA-2025-0154, UBUNTU-CVE-2025-2866, USN-7504-1

## What is CVE-2025-2866?

CVE-2025-2866 is a low-severity vulnerability in Libreoffice Libreoffice, published on 27 Apr 2025. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

Improper Verification of Cryptographic Signature vulnerability in LibreOffice allows PDF Signature Spoofing by Improper Validation.

In the affected versions of LibreOffice a flaw in the verification code for adbe.pkcs7.sha1 signatures could cause invalid signatures to be accepted as valid

This issue affects LibreOffice: from 24.8 before < 24.8.6, from 25.2 before < 25.2.2.

Weakness: CWE-347 (Improper Verification of Cryptographic Signature)

## Which versions are affected by CVE-2025-2866?

It affects 1 product.


Products: Libreoffice Libreoffice.

## How do I fix CVE-2025-2866?

Upgrade to a fixed version.

## Is CVE-2025-2866 being exploited?

There is no known exploitation of CVE-2025-2866 in the wild and no public exploit code.

## Other vulnerabilities in Libreoffice Libreoffice

- [CVE-2024-5261](https://insights.sbomify.com/CVE-2024-5261/): TLS certificate are not properly verified when utilizing LibreOfficeKit (critical 10.0)
- [CVE-2019-9855](https://insights.sbomify.com/CVE-2019-9855/): Windows 8.3 path equivalence handling flaw allows LibreLogo script execution (critical 9.8)
- [CVE-2018-14939](https://insights.sbomify.com/CVE-2018-14939/): Memory corruption in n/a (critical 9.8)
- [CVE-2017-8358](https://insights.sbomify.com/CVE-2017-8358/): Memory corruption in n/a (critical 9.8)
- [CVE-2017-7882](https://insights.sbomify.com/CVE-2017-7882/): Memory corruption in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-2866 and fix it if it is affected.

What it is: CVE-2025-2866 is a low-severity vulnerability in Libreoffice Libreoffice, published on 27 Apr 2025. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2025-2866 in the wild and no public exploit code.

Affected product: Libreoffice Libreoffice. 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-2025-2866/ (Markdown: https://insights.sbomify.com/CVE-2025-2866/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-2866
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-2866
- OSV: https://osv.dev/vulnerability/CVE-2025-2866

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-2866/
Summaries are generated and may contain mistakes; the official description above is the record.