Heap Buffer Overflow in LibreOffice Draw Affects PDF Imports
CVE-2026-63273

5.4MEDIUM

Key Information:

Vendor

The Document Foundation

Status
Libreoffice
Vendor
CVE Published:
22 September 2026

What is CVE-2026-63273?

LibreOffice Draw contains a vulnerability that can lead to a heap buffer overflow when importing encrypted PDF documents. This issue arises from the improper handling of decryption key lengths derived from the document's encryption dictionary. If this length exceeds the pre-defined key buffer size, it results in data being written beyond the allocated memory. The fixed versions of the software now ensure that any declared key lengths surpassing the buffer size are appropriately rejected, bolstering security during PDF document import processes.

Affected Version(s)

LibreOffice 26.2

References

https://www.libreoffice.org/about-us/security/advisories/...

CVSS V4

Score:
5.4
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
Low
Availability:
High
Attack Vector:
Local
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
Unknown

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Claude, found by Anthropic using agents to study the security of open-source projects
Ada Logics, validating and reporting
Caolán McNamara of Collabora Productivity
.