CVE-2026-8356: CWE-787 Out-of-bounds Write in The Document Foundation LibreOffice
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.
AI Analysis
Technical Summary
CVE-2026-8356 is a stack buffer overflow vulnerability in LibreOffice 26.2 related to importing legacy binary PPT files. The issue arises because two fixed-size colour tables are populated from a colour-replacement record without resetting the write position between the two passes. If the total colour count exceeds the table size, this results in out-of-bounds writes on the stack. The vulnerability is classified under CWE-787 (Out-of-bounds Write) and CWE-121 (Stack-based Buffer Overflow). No official fix or patch has been documented at this time.
Potential Impact
The vulnerability allows an attacker to cause a stack buffer overflow when importing crafted PPT files, potentially leading to memory corruption. This could result in application crashes or other undefined behavior. The CVSS score of 5.4 indicates a medium impact, with local attack vector and low complexity. There is no indication of known exploits in the wild.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, avoid opening untrusted legacy PPT files in LibreOffice 26.2 to reduce risk.
CVE-2026-8356: CWE-787 Out-of-bounds Write in The Document Foundation LibreOffice
Description
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.
CVSS v4.0
Score 5.4medium
Affected software
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-8356 is a stack buffer overflow vulnerability in LibreOffice 26.2 related to importing legacy binary PPT files. The issue arises because two fixed-size colour tables are populated from a colour-replacement record without resetting the write position between the two passes. If the total colour count exceeds the table size, this results in out-of-bounds writes on the stack. The vulnerability is classified under CWE-787 (Out-of-bounds Write) and CWE-121 (Stack-based Buffer Overflow). No official fix or patch has been documented at this time.
Potential Impact
The vulnerability allows an attacker to cause a stack buffer overflow when importing crafted PPT files, potentially leading to memory corruption. This could result in application crashes or other undefined behavior. The CVSS score of 5.4 indicates a medium impact, with local attack vector and low complexity. There is no indication of known exploits in the wild.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, avoid opening untrusted legacy PPT files in LibreOffice 26.2 to reduce risk.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- Document Fdn.
- Date Reserved
- 2026-05-11T18:42:20.783Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a303db60b89be6888695b25
Added to database: 06/15/2026, 18:00:22 UTC
Last enriched: 06/15/2026, 18:15:16 UTC
Last updated: 07/31/2026, 19:23:00 UTC
Views: 92
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