CVE-2026-55094

Taskcluster: Unauthenticated remote code execution in `web-server` via GraphQL `filter` argument (sift `$where`)

8.7 High

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.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: None

What an attacker can affect

Confidentiality: High
Integrity: None
Availability: None

Exploit likelihood

0.42%Down 0.3 points since Oct 1, 2026

What each source reports

CVE List Score used 8.7

Taskcluster: Unauthenticated remote code execution in `web-server` via GraphQL `filter` argument (sift `$where`)

Record: CVE-2026-55094
CVSS 4.0: 8.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
Weakness: CWE-20, CWE-94, CWE-95, CWE-250, CWE-306
Updated: 2026-11-02

EUVDEUVD-2026-90208 8.7

Record: EUVD-2026-90208
CVSS 4.0: 8.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
Updated: 2026-11-02

GitHub AdvisoriesGHSA-v484-996h-6h4h 8.7

Taskcluster is the task execution framework that supports Mozilla's continuous integration and...

Record: GHSA-v484-996h-6h4h
CVSS 4.0: 8.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Weakness: CWE-20
Updated: 2026-11-02

NVD 8.7

Record: CVE-2026-55094
CVSS 4.0: 8.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Weakness: CWE-20, CWE-94, CWE-95, CWE-250, CWE-306
Updated: 2026-11-02

OSV 8.7

Taskcluster: Unauthenticated remote code execution in `web-server` via GraphQL `filter` argument (sift `$where`)

Record: CVE-2026-55094
CVSS 4.0: 8.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
Weakness: CWE-20, CWE-250, CWE-306, CWE-94, CWE-95
Updated: 2026-11-02

Affected products

taskcluster

History

History
Recorded	Changed	Sources
Nov 2, 2026	first indexed	CVE List, EUVD, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-55094 is a high vulnerability (CVSS 8.7) in Taskcluster, published September 30, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.42%, the 36th percentile. No source names a fixed version.