CVE-2026-63274

LibreOffice Draw can import PDF documents. A heap buffer overflow existed when importing a stream object. The length of the stream was taken from the object's own dictionary and was not checked against the number of bytes actually present, so copying the stream read and wrote past the end of the buffer holding it. In fixed versions the declared length is clamped to the bytes actually read.

Credits

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

References