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PatchSiren cyber security CVE debrief

CVE-2026-6045 The Document Foundation CVE debrief

A heap buffer overflow existed in LibreOffice when importing an EMF+ gradient brush. The number of gradient blend points was read from the file and used to compute an allocation size, but that multiplication could overflow, so a small buffer was allocated and then filled as if it were large, writing past its end. In fixed versions, the blend-point count is checked against the data actually available before allocating.

Vendor
The Document Foundation
Product
LibreOffice
CVSS
MEDIUM 5.4
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-15
Original CVE updated
2026-06-15
Advisory published
2026-06-15
Advisory updated
2026-06-15

Who should care

Users of LibreOffice who open documents containing EMF+ graphics may be affected by this vulnerability.

Technical summary

The vulnerability occurs when importing an EMF+ gradient brush. The number of gradient blend points is read from the file and used to compute an allocation size. However, the multiplication can overflow, resulting in a small buffer being allocated and then filled as if it were large, leading to a heap buffer overflow.

Defensive priority

MEDIUM

Recommended defensive actions

  • Update LibreOffice to a fixed version.
  • Be cautious when opening documents from untrusted sources that contain EMF+ graphics.

Evidence notes

The CVE record indicates that the vulnerability has a CVSS score of 5.4 and a severity of MEDIUM.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-6045 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-6045

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-6045 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-6045

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.