CVE-2026-19884
Fix: eclipse-theia/theia#16809CVE-2026-19884 is a CWE-15 vulnerability. O3 Security confirms whether CVE-2026-19884 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
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…
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-19884.
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.
Detection & mitigation playbook
VulnerabilityDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for the affected component. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Remediation status
No patched version of the affected component has shipped for CVE-2026-19884 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-19884 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-19884. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-19884 in your dependencies?
O3 detects CVE-2026-19884 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.