dbcve.org
Stack-based Buffer OverflowWeakness · CWE-121

CVE-2026-8356

MEDIUM · 5.4 CVSS v4.0 Published 2026-06-15
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
57/100
Remediation priority · Elevated
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
LibreOffice can import presentations in the legacy binary PPT format. A stack buffer overflow existed when importing a colour-replacement record. Two fixed-size colour tables were filled from the file, but the write position was not reset between the two passes over the record, so a file whose combined colour counts exceeded the table size wrote past the end of the tables on the stack. In fixed versions the unused second pass is no longer read into those tables.

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 a stack buffer overflow vulnerability in its legacy binary PPT format importer. When importing colour-replacement records, the application fills two fixed-size colour tables from the file without resetting the write position between two passes. A malicious PPT file with combined colour counts exceeding the table size can write past the end of the tables onto the stack, potentially allowing arbitrary code execution.

MitigationUpdate to the fixed version of LibreOffice. As a temporary measure, avoid opening untrusted or unexpected PPT files in LibreOffice.

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

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
Authentication
X
User interaction
P
Scope
X

CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

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. Verify LibreOffice is installed
    Run command: which libreoffice (Linux/macOS) or check Programs and Features (Windows)
    Affected if LibreOffice is not installed on the system
  2. Determine the installed LibreOffice version
    Run: libreoffice --version (Linux/macOS) or check via Help > About in the application (Windows)
    Affected if The version returned cannot be compared to the fixed version
  3. Check if the legacy binary PPT importer is available
    Attempt to open a PPT file in LibreOffice, or check File > Open supported formats for .ppt legacy binary support
    Affected if The legacy binary PPT format is supported and can be used to open files
  4. Compare your version to the fixed release
    Locate the specific CVE disclosure to obtain the exact fixed version number, then compare your installed version against it
    Affected if Your installed version is older than the fixed version and the legacy PPT importer is enabled
  5. Inspect file association for PPT files
    Check system file associations or LibreOffice preferences to confirm .ppt files are set to open with LibreOffice
    Affected if LibreOffice is configured as the default handler for legacy PPT files and you may open untrusted files

You are affected if you have an installed LibreOffice version older than the fixed release and the legacy binary PPT importer is available or enabled, allowing you to open potentially malicious PPT files.

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.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Update to the fixed version of LibreOffice. As a temporary measure, avoid opening untrusted or unexpected PPT files in LibreOffice.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing3.0 h
  • Review / QA2.0 h
9.0 hours of engineering $1,570
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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-2026-8356 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