CVE-2026-63273: CWE-787 Out-of-bounds Write in The Document Foundation LibreOffice
LibreOffice Draw can import PDF documents. A heap buffer overflow existed when importing an encrypted document. The length of the decryption key was taken from the document's own encryption dictionary and was used to fill a fixed size key buffer without being checked against it, so a length larger than that buffer wrote past its end. In fixed versions a declared key length larger than the buffer is rejected.
AI Analysis
Technical Summary
This vulnerability (CWE-787) in LibreOffice Draw involves a heap buffer overflow triggered during the import of encrypted PDF documents. The decryption key length is read from the document's encryption dictionary and used to fill a fixed-size key buffer without bounds checking, leading to a potential out-of-bounds write. The issue is addressed in fixed versions by rejecting any declared key length that exceeds the buffer size.
Potential Impact
The heap buffer overflow could lead to memory corruption, potentially causing application crashes or other undefined behavior. The CVSS 4.0 score is 5.4 (medium severity), indicating limited attack vector (local), low complexity, no privileges required, user interaction needed, and high impact on availability. There are no known exploits in the wild.
Mitigation Recommendations
A fix is available that rejects decryption key lengths larger than the buffer size. Users should update to the fixed version to remediate this vulnerability. No additional mitigation steps are indicated.
CVE-2026-63273: CWE-787 Out-of-bounds Write in The Document Foundation LibreOffice
Description
LibreOffice Draw can import PDF documents. A heap buffer overflow existed when importing an encrypted document. The length of the decryption key was taken from the document's own encryption dictionary and was used to fill a fixed size key buffer without being checked against it, so a length larger than that buffer wrote past its end. In fixed versions a declared key length larger than the buffer is rejected.
CVSS v4.0
Score 5.4medium
Affected software
The Document Foundation
LibreOffice
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability (CWE-787) in LibreOffice Draw involves a heap buffer overflow triggered during the import of encrypted PDF documents. The decryption key length is read from the document's encryption dictionary and used to fill a fixed-size key buffer without bounds checking, leading to a potential out-of-bounds write. The issue is addressed in fixed versions by rejecting any declared key length that exceeds the buffer size.
Potential Impact
The heap buffer overflow could lead to memory corruption, potentially causing application crashes or other undefined behavior. The CVSS 4.0 score is 5.4 (medium severity), indicating limited attack vector (local), low complexity, no privileges required, user interaction needed, and high impact on availability. There are no known exploits in the wild.
Mitigation Recommendations
A fix is available that rejects decryption key lengths larger than the buffer size. Users should update to the fixed version to remediate this vulnerability. No additional mitigation steps are indicated.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- Document Fdn.
- Date Reserved
- 2026-07-16T08:17:05.512Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6ab2677df7a7c541061982d7
Added to database: 09/22/2026, 11:33:17 UTC
Last enriched: 09/22/2026, 11:48:24 UTC
Last updated: 09/23/2026, 01:58:07 UTC
Views: 15
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