Medium severity · published Sep 22, 2026
CVE-2026-63273
Heap buffer overflow in PDF import encryption handling
5.4
CVSS
0.1%
EPSS
No
On KEV
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.
Exploitation
Is it being used?
Exploit prediction (EPSS)0.1% · higher than 2% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
LI
LibreOffice · The Document Foundation
26.2 before < 26.2.5 · source: vendor
In the news
VulnerabilityHigh
ZDI-26-783: LibreOffice PDF File Parsing Out-Of-Bounds Write Remote Code Execution Vulnerability
This vulnerability allows remote attackers to execute arbitrary code on affected installations of LibreOffice. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file. The ZDI has assigned a CVSS rating of 7.8. The following CVEs are assigned: CVE-2026-63273.
Oct 16, 2026·Zero Day Initiative
Affected product
LI
LibreOffice
The Document Foundation
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