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

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-04-27 · updated 2026-06-17
Weakness: CWE-347

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.

Affected products

The Document Foundation LibreOffice: from 24.8.0.1 before 24.8.6.0; from 25.2.0.1 before 25.2.2; 24.8.0.0-alpha1, 24.8.0.0-beta1, 25.2.0.0-alpha1, 25.2.0.0-beta1 — fixed in 24.8.6.0, 25.2.2

How to fix

Upgrade to a fixed version: The Document Foundation LibreOffice 24.8.6.0, 25.2.2. Check the vendor advisory for mitigations.

References

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