CVE-2026-6039: CWE-787 Out-of-bounds Write in The Document Foundation LibreOffice
LibreOffice can import drawings in the DXF format used by CAD software. A heap buffer overflow existed when importing a DXF polyline. The point count taken from the file was truncated to a 16-bit value when the point buffer was sized, while the full count was used to fill it, so a polyline whose point count exceeded the 16-bit range was written past the end of the buffer. In fixed versions such oversized polylines are rejected.
AI Analysis
Technical Summary
CVE-2026-6039 is a heap buffer overflow vulnerability in LibreOffice's DXF import functionality. The flaw arises from truncating the polyline point count to 16 bits when allocating the buffer, while the full point count is used to fill it. This mismatch allows writing beyond the allocated buffer boundary if the polyline's point count exceeds the 16-bit limit. The Document Foundation has addressed this by rejecting oversized polylines in fixed versions.
Potential Impact
The vulnerability can lead to heap corruption due to out-of-bounds writes when importing specially crafted DXF files containing polylines with excessive point counts. This may cause application crashes or potentially enable code execution or other memory corruption impacts. The CVSS 4.0 base score is 5.4 (medium severity), reflecting local attack vector with low complexity and partial impact on confidentiality, integrity, and high impact on availability.
Mitigation Recommendations
No official patch or remediation level is currently confirmed. Fixed versions reject oversized polylines, but no specific fixed versions or patches are provided in the data. Users should monitor The Document Foundation advisories for official updates and avoid importing untrusted DXF files with large polylines until a fix is available.
CVE-2026-6039: CWE-787 Out-of-bounds Write in The Document Foundation LibreOffice
Description
LibreOffice can import drawings in the DXF format used by CAD software. A heap buffer overflow existed when importing a DXF polyline. The point count taken from the file was truncated to a 16-bit value when the point buffer was sized, while the full count was used to fill it, so a polyline whose point count exceeded the 16-bit range was written past the end of the buffer. In fixed versions such oversized polylines are rejected.
CVSS v4.0
Score 5.4medium
Affected software
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-6039 is a heap buffer overflow vulnerability in LibreOffice's DXF import functionality. The flaw arises from truncating the polyline point count to 16 bits when allocating the buffer, while the full point count is used to fill it. This mismatch allows writing beyond the allocated buffer boundary if the polyline's point count exceeds the 16-bit limit. The Document Foundation has addressed this by rejecting oversized polylines in fixed versions.
Potential Impact
The vulnerability can lead to heap corruption due to out-of-bounds writes when importing specially crafted DXF files containing polylines with excessive point counts. This may cause application crashes or potentially enable code execution or other memory corruption impacts. The CVSS 4.0 base score is 5.4 (medium severity), reflecting local attack vector with low complexity and partial impact on confidentiality, integrity, and high impact on availability.
Mitigation Recommendations
No official patch or remediation level is currently confirmed. Fixed versions reject oversized polylines, but no specific fixed versions or patches are provided in the data. Users should monitor The Document Foundation advisories for official updates and avoid importing untrusted DXF files with large polylines until a fix is available.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- Document Fdn.
- Date Reserved
- 2026-04-09T16:29:22.953Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a303db60b89be6888695b19
Added to database: 6/15/2026, 6:00:22 PM
Last enriched: 6/15/2026, 6:15:37 PM
Last updated: 6/15/2026, 8:17:52 PM
Views: 2
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