CVE-2026-55428: coder Improper Authorization

Vulnerability summary

CVE-2026-55428 is a high (CVSS 8.2) Improper Authorization vulnerability in coder. EPSS estimates a 0.40% chance of exploitation in the next 30 days, higher than 33.2% of scored vulnerabilities.

Timeline

1. 07-07-2026
   PublishedVulnerability first disclosed.
2. 08-07-2026
   Last modifiedVulnerability information updated.

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.

• CWE-285Improper AuthorizationThe product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action.
• CWE-863Incorrect AuthorizationThe product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.