---
cve: "CVE-2026-55431"
severity: "HIGH"
cvss: 7.7
epss: "18%"
vendor: "coder"
kev: false
exploited: false
published: "2026-07-08 01:16:27"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-09T06:04:43+02:00"
---

# CVE-2026-55431

> 7.7 HIGH · 🧪 PoC

## Beschreibung

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-Vektor

```
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:N
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Hoch | good |
| PR Privilegien | Gering | warn |
| UI Interaktion | Erforderlich | good |
| S Scope | Verändert | bad |
| C Vertraulichkeit | Hoch | bad |
| I Integrität | Hoch | bad |
| A Verfügbarkeit | Keine | good |

## Patch verfügbar (OSV)

- 77253bfc55665027a374a5d2fb70f4ff74410326 (Commit)
- 0374b00b63bc5043a507194f284ef298e0ea3b52 (Commit)

## Referenzen

- <https://github.com/coder/coder/security/advisories/GHSA-v54h-cp2w-9x4g>
- <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>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-55431) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_