CVE-2026-8356 Stack buffer overflow in PPT presentation import
A stack buffer overflow in LibreOffice's PPT import allows attackers to execute arbitrary code via a malicious presentation file.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-8356?
CVE-2026-8356 is a medium-severity memory corruption vulnerability in The Document Foundation LibreOffice, published on 15 Jun 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official 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.
Which versions are affected by CVE-2026-8356?
How do I fix CVE-2026-8356?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-8356 being exploited?
There is no known exploitation of CVE-2026-8356 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-8356, GHSA-8r7p-3qw5-wxm5, UBUNTU-CVE-2026-8356.