Auth bypass in Coder
CVE-2026-55428
Coder allows organizations to provision remote development environments via Terraform. Prior to versions 2.29.7, 2.32.7, 2.33.8, and 2.34.2, the tailnet coordinator validates that an agent's `Addresses` derive from its authenticated UUID but applies no equivalent check to `AllowedIPs`. The coordinator forwards agent-supplied `AllowedIPs` verbatim to tunnel peers which install them into the WireGuard peer configuration. The fix in versions 2.29.7, 2.32.7, 2.33.8, and 2.34.2 validates each `AllowedIPs` prefix against the authenticating agent's UUID just like `Addresses`. As a workaround, monitor coordinator logs for agents advertising unexpected `AllowedIPs` prefixes.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.2 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N.
EPSS exploit prediction
EPSS: 0.004 (32.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 33rd percentile — 32.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000
Affected products
- Coder — versions >= 2.34.0, < 2.34.2, >= 2.33.0, < 2.33.8, >= 2.30.0, < 2.32.7
Weakness classification (CWE)
References
- github.com/coder/coder/pull/26144 (Patch, Issue Tracking)
- github.com/coder/coder/releases/tag/v2.29.17 (Release Notes)
- github.com/coder/coder/releases/tag/v2.32.7 (Release Notes)
- github.com/coder/coder/releases/tag/v2.33.8 (Release Notes)
- github.com/coder/coder/releases/tag/v2.34.2 (Release Notes)
- github.com/coder/coder/security/advisories/GHSA-wrq8-fcv5-8hvp (Patch, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-55428?
- CVE-2026-55428 is a high-severity vulnerability in Coder, classified under Improper Authorization. CVSS score: 8.2/10. Published 2026-07-08.
- How severe is CVE-2026-55428?
- High severity. CVSS v3 base score is 8.2 out of 10.