{"cve":"CVE-2026-55431","nvd":{"published":"2026-07-08T01:16:27.480","modified":"2026-07-08T19:42:45.880","status":"Analyzed","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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","score":6.1},"cwes":["CWE-522","CWE-601"],"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"],"products":["coder:coder"],"source":"nvd","synced_at":"2026-10-19T22:42:16.820116992+00:00"},"epss":{"cve":"CVE-2026-55431","score":0.00336,"percentile":0.27051,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-v54h-cp2w-9x4g","url":"https://osv.dev/vulnerability/GHSA-v54h-cp2w-9x4g","summary":"Coder's session token leaked to arbitrary hosts via `coder open app` for external workspace apps","modified":"2026-07-07T20:41:29.070140845Z","packages":[{"ecosystem":"Go","name":"github.com/coder/coder/v2","purl":"pkg:golang/github.com/coder/coder/v2","ranges":[">=2.34.0 <2.34.2"],"fixed":["2.34.2"]},{"ecosystem":"Go","name":"github.com/coder/coder/v2","purl":"pkg:golang/github.com/coder/coder/v2","ranges":[">=2.33.0 <2.33.8"],"fixed":["2.33.8"]},{"ecosystem":"Go","name":"github.com/coder/coder/v2","purl":"pkg:golang/github.com/coder/coder/v2","ranges":[">=2.30.0 <2.32.7"],"fixed":["2.32.7"]},{"ecosystem":"Go","name":"github.com/coder/coder/v2","purl":"pkg:golang/github.com/coder/coder/v2","ranges":["<2.29.17"],"fixed":["2.29.17"]}]},{"id":"GO-2026-5924","url":"https://osv.dev/vulnerability/GO-2026-5924","summary":"Coder's session token leaked to arbitrary hosts via `coder open app` for external workspace apps in github.com/coder/coder","modified":"2026-07-07T20:30:16.373105936Z","packages":[{"ecosystem":"Go","name":"github.com/coder/coder","purl":"pkg:golang/github.com/coder/coder","ranges":["all versions"],"fixed":[]},{"ecosystem":"Go","name":"github.com/coder/coder/v2","purl":"pkg:golang/github.com/coder/coder/v2","ranges":["<2.29.17",">=2.30.0 <2.32.7",">=2.33.0 <2.33.8",">=2.34.0 <2.34.2"],"fixed":["2.29.17","2.32.7","2.33.8","2.34.2"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}