CVE-2026-19884 Code injection in Eclipse Theia
Attackers can execute arbitrary commands by tricking users into opening a malicious repository in Eclipse Theia, bypassing workspace trust checks.
- 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
- None listed
What is CVE-2026-19884?
CVE-2026-19884 is a high-severity code injection vulnerability in Eclipse Theia, published on 14 Aug 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
In Eclipse Theia versions up to and including 1.69.0, opening a folder starts source control integration without requiring the user to trust the folder first. This affects applications built on Theia that include the git integration, such as the Theia IDE. Both Theia's own `@theia/git` extension and the builtin VS Code `git` extension run git commands such as `git status` as soon as a repository is detected. Since git honors repository-local configuration, a folder containing an attacker-controlled `.git/config` with `core.fsmonitor` (or a comparable hook-like setting) causes the configured command to be executed. The configuration can be delivered by burying a bare repository inside a regular repository (OVE-20210718-0001), so cloning an attacker-supplied repository and opening it in a Theia-based application is sufficient to execute arbitrary commands with the privileges of the user, without any confirmation prompt.
As of 1.70.0, plugins that declare `capabilities.untrustedWorkspaces.supported: false`, which includes the builtin git extension, are no longer loaded or activated in an untrusted workspace, and the deprecated `@theia/git` extension has been removed, so no git command is executed against an untrusted folder.
Which versions are affected by CVE-2026-19884?
How do I fix CVE-2026-19884?
No fix has been published for CVE-2026-19884 yet. Limit exposure of the affected software until one is available.
Upgrade, and never evaluate templates, expressions or code built from user input. More about Code injection.
Is CVE-2026-19884 being exploited?
There is no known exploitation of CVE-2026-19884 in the wild and no public exploit code.
Sources
Also known as GHSA-4g73-gqqh-rfjc.