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LibreofficeApplication

CVE-2026-4430

HIGH · 7.8 CVSS v3.1 Published 2026-05-07
Fix available
A fix is available. Upgrade to 25.8.7.0 / 26.2.3.0 or later.
See remediation →
81/100
Remediation priority · High
No privileges

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Out-of-bounds write vulnerability in The Document Foundation LibreOffice via crafted OOXML documents with mismatched encryption salt parameters. This issue affects LibreOffice: from 26.2 before 26.2.3, from 25.8 before 25.8.7.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

LibreOffice contains an out-of-bounds write vulnerability when parsing crafted OOXML documents with mismatched encryption salt parameters. This memory corruption issue can be triggered by opening specially malicious documents, potentially leading to arbitrary code execution or denial of service.

MitigationUpdate LibreOffice to version 26.2.3 or later (for 26.2.x) or 25.8.7 or later (for 25.8.x). Avoid opening untrusted OOXML documents from unknown sources until the update is applied.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
LibreofficeApplication
Affected:>= 25.8.0.0, < 25.8.7.0>= 26.2.0.0, < 26.2.3.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
None
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify LibreOffice version on Windows
    Open LibreOffice Writer, go to Help > About LibreOffice to view the installed version number
    Affected if Version displayed is >= 25.8.0.0 and < 25.8.7.0, or >= 26.2.0.0 and < 26.2.3.0
  2. Identify LibreOffice version on Linux
    Run command: libreoffice --version or rpm -q libreoffice or dpkg -l libreoffice* depending on package manager
    Affected if Version displayed is >= 25.8.0.0 and < 25.8.7.0, or >= 26.2.0.0 and < 26.2.3.0
  3. Identify LibreOffice version on macOS
    Open LibreOffice app, click LibreOffice menu > About LibreOffice, or run: defaults read /Applications/LibreOffice.app/Contents/Info CFBundleShortVersionString
    Affected if Version displayed is >= 25.8.0.0 and < 25.8.7.0, or >= 26.2.0.0 and < 26.2.3.0
  4. Verify OOXML document handling is in use
    Check if the application can open .docx, .xlsx, or .pptx files (OOXML formats). This is enabled by default in LibreOffice; no configuration change required.
    Affected if OOXML file format support is present (default state)
  5. Assess exposure to untrusted documents
    Review document handling practices: determine if LibreOffice is used to open files from untrusted or unknown sources, particularly OOXML documents
    Affected if Users routinely open OOXML documents from untrusted or unknown sources without prior validation

A user is affected if their installed LibreOffice version falls within 25.8.0.0 to 25.8.6.x or 26.2.0.0 to 26.2.2.x and they open maliciously crafted OOXML documents.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 25.8.7.0 / 26.2.3.0 or later
Fixed in 25.8.7.026.2.3.0
Interim mitigation

Update LibreOffice to version 26.2.3 or later (for 26.2.x) or 25.8.7 or later (for 25.8.x). Avoid opening untrusted OOXML documents from unknown sources until the update is applied.

Recommended fix High confidence

LibreOffice 26.2.3.0 or later (or 25.8.7.0 or later for the 25.8.x branch)

  1. Check current LibreOffice version via Help > About LibreOffice or command line (libreoffice --version)
  2. For LibreOffice 26.2.x: Upgrade to version 26.2.3.0 or later
  3. For LibreOffice 25.8.x: Upgrade to version 25.8.7.0 or later
  4. Download the appropriate fixed version from the official LibreOffice website (www.libreoffice.org)
  5. Uninstall the current LibreOffice installation
  6. Install the downloaded fixed version
  7. Verify the installed version matches the fixed release
Caveat Minor version upgrades typically have minimal breaking changes; ensure documents are backed up before upgrading

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Libreoffice Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing4.0 h
  • Review / QA2.0 h
10.0 hours of engineering $1,720
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,752.

Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-4430 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data