CVE-2026-55431: Coder allows organizations to provision remote develop
CVE-2026-55431 analysis covering impact, affected products, versions, remediation, and cross-checked defender guidance.
CVE-2026-55431 is a vulnerability published by NVD on 7/8/2026.
What happened
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, `coder open app` opens external workspace-app URLs without validating the scheme or host. When an external app URL contains the `$SESSION_TOKEN` placeholder the CLI replaces it with the user's real session token before handing the URL to the OS open handler. Practical exploitation requires the victim to run `coder open app` against a workspace whose external app definition the attacker controls. Only a malicious template author can control external app URLs. The fix in versions 2.29.7, 2.32.7, 2.33.8, and 2.34.2 applies a URL-scheme allowlist in the CLI and limits `$SESSION_TOKEN` substitution to trusted destinations like the web frontend. As a workaround, avoid running `coder open app` for untrusted workspaces.
Affected products and versions
- coder coder unspecified version (before 2.29.17)
- coder coder unspecified version (from 2.30.0 before 2.32.7)
- coder coder unspecified version (from 2.33.0 before 2.33.8)
- coder coder unspecified version (from 2.34.0 before 2.34.2)
Severity and weakness
CVSS: HIGH 7.7. Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:N.
Weaknesses: CWE-522, CWE-601.
Known exploitation
No CISA KEV entry is currently attached to the NVD record.
What defenders should do
- Identify whether the affected product and version range exists in production.
- Review vendor advisories and release notes before change windows.
- Patch, upgrade, disable the vulnerable component, or apply vendor mitigations.
- Verify the running version after deployment, not only the package inventory.
Official and supporting references
- https://github.com/coder/coder/pull/26146
- 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
- https://github.com/coder/coder/security/advisories/GHSA-v54h-cp2w-9x4g