Answer in brief
CVE-2026-55431 records a High severity (CVSS 7.7) vulnerability in Coder's session token leaked to arbitrary hosts via `coder open app` for external workspace apps. The current sources do not mark it as known exploited. The current feed maps coder/coder (generic), github.com/coder/coder/v2 (go), github.com/coder/coder/v2 (go), github.com/coder/coder/v2 (go) and additional mapped packages. Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.7. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps coder/coder (generic), github.com/coder/coder/v2 (go), github.com/coder/coder/v2 (go), github.com/coder/coder/v2 (go) and additional mapped packages. Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| coder/codergeneric | >= 2.34.0, < 2.34.2 || >= 2.33.0, < 2.33.8 || >= 2.30.0, < 2.32.7 || < 2.29.17 | Not reported |
| github.com/coder/coder/v2go | >=2.34.0,<2.34.2 | 2.34.2 |
| github.com/coder/coder/v2go | >=2.33.0,<2.33.8 | 2.33.8 |
| github.com/coder/coder/v2go | >=2.30.0,<2.32.7 | 2.32.7 |
| github.com/coder/coder/v2go | <2.29.17 | 2.29.17 |
Published upstream
Jul 8, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Jul 8, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jul 6, 2026
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.
Quoted source text, attributed separately from HOL analysis.