CVE-2025-2866: Improper Verification of Cryptographic Signature vulnerability in LibreOffice allows PDF Signature Spoofing by

Routine

MEDIUM 5.5UPGRADE

CVE-2025-2866 is a medium-severity flaw (CVSS 5.5) affecting libreoffice. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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.

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	5.5 (Medium)
Attack vector	Local
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.1% (top 98%)
CISA exploited list	No
Weakness	CWE-347
Published	2025-04-27
Last modified	2026-06-17

Publisher (CNA): Document Foundation, The · Vendor: libreoffice

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2025-04-27 19:15 UTCPublished CVE record published
2026-06-17 09:07 UTCUpdated Record last modified

libreoffice libreoffice UPGRADE

Affected: >= 24.8.0.1 and < 24.8.6.0 · >= 25.2.0.1 and < 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

Safe to downgrade to: a release before 24.8.0.0

1. Check installed version

apt-cache policy libreoffice || rpm -q libreoffice || libreoffice --version

2. UPGRADE to 24.8.6.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade libreoffice

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade libreoffice

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 24.8.0.0 (Debian / Ubuntu)

apt-cache madison libreoffice sudo apt install libreoffice=<VERSION_BEFORE_24.8.0.0> sudo apt-mark hold libreoffice

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list libreoffice sudo dnf downgrade libreoffice-<VERSION_BEFORE_24.8.0.0> sudo dnf versionlock add libreoffice

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2025-2866?

libreoffice: upgrade to 24.8.6.0, 25.2.2. Exact commands for each OS are on this page.

Is CVE-2025-2866 being exploited?

CVE-2025-2866 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2025-2866 affect?

CVE-2025-2866 affects libreoffice. Severity is medium (CVSS 5.5). 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 c

How urgent is CVE-2025-2866?

Priority 20/100. No elevated risk signals yet.

Software pages

LibreOffice vulnerabilities

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References

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