CVE-2026-55094 Taskcluster: Unauthenticated remote code execution in `web-server` via GraphQL `filter` argument (sift `$where`)
Unauthenticated attackers can execute arbitrary code on Taskcluster deployments if an anonymous role exposes the GraphQL endpoint.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-55094?
CVE-2026-55094 is a high-severity code injection vulnerability in taskcluster, published on 30 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Taskcluster is the task execution framework that supports Mozilla's continuous integration and release processes. Prior to version 100.3.0, Taskcluster is vulnerable to unauthenticated RCE on Taskcluster deployments with an anonymous role that exposes the GraphQL endpoint and parses filter arguments using the sift library. This issue has been patched in version 100.3.0.
Which versions are affected by CVE-2026-55094?
How do I fix CVE-2026-55094?
No fix has been published for CVE-2026-55094 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-2026-55094 being exploited?
There is no known exploitation of CVE-2026-55094 in the wild and no public exploit code.
Sources
Also known as GHSA-ccv5-c45x-2q38, GHSA-v484-996h-6h4h.