CVE-2026-63277 RCE via calcext:data-mappings, sql provider and jdbc connector
Attackers can execute arbitrary Java code by tricking users into opening a LibreOffice Calc document with a malicious external data source link.
- 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-2026-63277?
CVE-2026-63277 is a high-severity code injection vulnerability in The Document Foundation LibreOffice, published on 5 Oct 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 Calc can link a cell range to an external data source, and the link is saved in the document. A document could name a Java database driver for such a link to be loaded from a remote location, so opening the document could run Java code from that location. In fixed versions an entry in a Java class path has to be a file URL.
Weakness: CWE-829
Which versions are affected by CVE-2026-63277?
How do I fix CVE-2026-63277?
Apply the vendor's patch.
Upgrade, and never evaluate templates, expressions or code built from user input. More about Code injection.
Is CVE-2026-63277 being exploited?
There is no known exploitation of CVE-2026-63277 in the wild and no public exploit code.
Public exploit code: 1 proofs of concept on GitHub.
Sources
Also known as DEBIAN-CVE-2026-63277, ECHO-4e8e-5028-bd77, GHSA-5jx8-5g92-5w59, MINI-qc23-wv85-h58x, UBUNTU-CVE-2026-63277.