CVE-2026-55431 Details
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, `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.
A vulnerability exists in Coder's handling of external application URLs within remote development environments provisioned via Terraform. Prior to versions 2.29.7, 2.32.7, 2.33.8, and 2.34.2, the command 'coder open app' would open external workspace application URLs without validating the scheme or host. This oversight allowed for the exfiltration of session tokens. When an external app URL included the '$SESSION_TOKEN' placeholder, the Coder CLI would replace it with the user's actual session token before passing the URL to the operating system's open handler. Exploitation of this vulnerability requires the user to execute 'coder open app' in a workspace where the external app definition is controlled by an attacker. Only a malicious template author can manipulate external app URLs.
Users should upgrade to Coder versions 2.29.17, 2.32.7, 2.33.8, or 2.34.2. Instructions for upgrading can be found in the Coder documentation.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed Jul 8, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/coder/coder/pull/26146 | [email protected] | Issue TrackingPatch |
| https://github.com/coder/coder/releases/tag/v2.29.17 | [email protected] | Release Notes |
| https://github.com/coder/coder/releases/tag/v2.32.7 | [email protected] | Release Notes |
| https://github.com/coder/coder/releases/tag/v2.33.8 | [email protected] | Release Notes |
| https://github.com/coder/coder/releases/tag/v2.34.2 | [email protected] | Release Notes |
| https://github.com/coder/coder/security/advisories/GHSA-v54h-cp2w-9x4g | [email protected] | PatchVendor Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-522 | Insufficiently Protected Credentials | [email protected] |
| CWE-601 | URL Redirection to Untrusted Site ('Open Redirect') | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| coder coder | < 2.29.17 >= 2.30.0, < 2.32.7 >= 2.33.0, < 2.33.8 >= 2.34.0, < 2.34.2 |
CPE
Remediation
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Change History
3 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 8, 2026 | Initial Analysis | [email protected] |
| Jul 8, 2026 | CVE Modified | CISA-ADP |
| Jul 8, 2026 | New CVE Received | [email protected] |