CVE-2025-2866

PDF signature spoofing via unchecked SignatureValue

Published Apr 27, 2025 · Updated Nov 3, 2025

Improper PDF signature verification in LibreOffice 24.8 before 24.8.6 and 25.2 before 25.2.2 allows attackers to spoof valid signatures. The adbe.pkcs7.sha1 verifier compared document hashes but never checked the SignerInfo SignatureValue against the public key. A user must open a crafted PDF, after which LibreOffice can display an invalid document signature as valid without exposing or altering file contents.

CVSS severity5.5
Medium
EPSS probability0.11%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper PDF signature verification in LibreOffice 24.8 before 24.8.6 and 25.2 before 25.2.2 allows attackers to spoof valid signatures. The adbe.pkcs7.sha1 verifier compared document hashes but never checked the SignerInfo SignatureValue against the public key. A user must open a crafted PDF, after which LibreOffice can display an invalid document signature as valid without exposing or altering file contents.

The record

CVE
CVE-2025-2866
Published
Apr 27, 2025
Updated
Nov 3, 2025
Vendor
The Document Foundation
Product
LibreOffice
Classifications
CWE-347
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 27, 2025CVE publishedPublication date reported by the CVE source.
  2. Nov 3, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=24.8 << 24.8.6
  2. Affected versionversion=25.2 << 25.2.2

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

The Document Foundation · LibreOfficeversion=24.8 << 24.8.6; version=25.2 << 25.2.2

Published CVSS scores

5.5UbuntuCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-347Improper Verification of Cryptographic Signature

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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