CVE-2026-55428
Coder: Route hijacking through lack of validation of agent-supplied AllowedIPs in tailnet coordinator
- State
- Published
- Severity
- 8.2 High
- Published
- Jul 7, 2026
- Updated
- Jul 8, 2026
- Reserved
- Jun 16, 2026
Description
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 8.2 High | CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N | GitHub_M |
Weaknesses
Affected Products
| Product | Versions |
|---|---|
codercoder |
|
References
- https://github.com/coder/coder/security/advisories/GHSA-wrq8-fcv5-8hvp
- https://github.com/coder/coder/pull/26144
- https://github.com/coder/coder/releases/tag/v2.29.17
- https://github.com/coder/coder/releases/tag/v2.32.7
- https://github.com/coder/coder/releases/tag/v2.33.8
- https://github.com/coder/coder/releases/tag/v2.34.2
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