Coder vulnerable to OIDC account takeover via email-based user matching and email_verified bypass
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- High · High · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-287.
Summary
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, two flaws in Coder's OIDC login chained into account takeover. Email-based user matching fell back to linking by email without checking for an existing link to a different IdP subject and the `email_verified` claim was only enforced when present as a boolean `false` so an absent or non-boolean claim was treated as verified. The fix in versions 2.29.7, 2.32.7, 2.33.8, and 2.34.2 restricts the email fallback to first-time and legacy linking and defaults `email_verified` to false when the claim is absent or of an unexpected type. As a workaround, configure the OIDC provider to disallow self-registration or to require email verification before issuing tokens.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| coder | coder | 2.34.0 to before 2.34.2; 2.33.0 to before 2.33.8; 2.30.0 to before 2.32.7; before 2.29.17 | 2.34.2, 2.33.8, 2.32.7, 2.29.17 | Patch available | CNA |
| — | github.com/coder/coder/v2 (Go) | 2.34.0 to before 2.34.2 | 2.34.2 | Patch available | GHSA-9r87-mvcw-x35f |
| — | github.com/coder/coder/v2 (Go) | 2.33.0 to before 2.33.8 | 2.33.8 | Patch available | GHSA-9r87-mvcw-x35f |
| — | github.com/coder/coder/v2 (Go) | 2.30.0 to before 2.32.7 | 2.32.7 | Patch available | GHSA-9r87-mvcw-x35f |
| — | github.com/coder/coder/v2 (Go) | before 2.29.17 | 2.29.17 | Patch available | GHSA-9r87-mvcw-x35f |
- coder Vendorcoder Affected 2.34.0 to before 2.34.2; 2.33.0 to before 2.33.8; 2.30.0 to before 2.32.7; before 2.29.17 Fixed in 2.34.2, 2.33.8, 2.32.7, 2.29.17 Patch available CNA
- github.com/coder/coder/v2 (Go) Vendor— Affected 2.34.0 to before 2.34.2 Fixed in 2.34.2 Patch available GHSA-9r87-mvcw-x35f
- github.com/coder/coder/v2 (Go) Vendor— Affected 2.33.0 to before 2.33.8 Fixed in 2.33.8 Patch available GHSA-9r87-mvcw-x35f
- github.com/coder/coder/v2 (Go) Vendor— Affected 2.30.0 to before 2.32.7 Fixed in 2.32.7 Patch available GHSA-9r87-mvcw-x35f
- github.com/coder/coder/v2 (Go) Vendor— Affected before 2.29.17 Fixed in 2.29.17 Patch available GHSA-9r87-mvcw-x35f
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:coder:coder:*:*:*:*:*:go:*:* | before 2.29.17; 2.30.0 to before 2.32.7; 2.33.0 to before 2.33.8; 2.34.0 to before 2.34.2 | Vulnerable | coder |
- cpe:2.3:a:coder:coder:*:*:*:*:*:go:*:* Versions before 2.29.17; 2.30.0 to before 2.32.7; 2.33.0 to before 2.33.8; 2.34.0 to before 2.34.2 Vulnerable ·coder
Remediation
- Fix · CNA coder (coder) Fixed in 2.34.2, 2.33.8, 2.32.7, 2.29.17
- Fix · GHSA-9r87-mvcw-x35f github.com/coder/coder/v2 (Go) Fixed in 2.34.2 Advisory →
- Fix · GHSA-9r87-mvcw-x35f github.com/coder/coder/v2 (Go) Fixed in 2.33.8 Advisory →
- Fix · GHSA-9r87-mvcw-x35f github.com/coder/coder/v2 (Go) Fixed in 2.32.7 Advisory →
- Fix · GHSA-9r87-mvcw-x35f github.com/coder/coder/v2 (Go) Fixed in 2.29.17 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-55075
- 2026-10-03 Alias added: GHSA-9r87-mvcw-x35f
References
Patch 3
More Coder vulnerabilities
- TI-2026-34071 Coder: PKCS#7 signature bypass in Azure instance identity allows unauthenticated agent token theft CVSS 3.1CRITICAL 9.1
- TI-2026-32394 Coder vulnerable to workspace auto-creation via crafted URL parameters without user consent CVSS 3.1HIGH 8.8
- TI-2024-18523 Coder's OIDC authentication allows email with partially matching domain to register CVSS 3.1HIGH 8.2
- TI-2026-39997 Coder's workspace app upsert allows cross-workspace agent rebinding via user-controlled app ID CVSS 3.1HIGH 8.7
- TI-2026-39996 Coder: Route hijacking through lack of validation of agent-supplied AllowedIPs in tailnet coordinator CVSS 3.1HIGH 8.2
- TI-2026-39995 Coder vulnerable to SSH config injection via unsanitized server-supplied values in `coder config-ssh` CVSS 3.1HIGH 8.3
Sources
- CVE-2026-55075 · CVE Program
- CVE-2026-55075 · NVD
- FIRST EPSS
- GHSA-9r87-mvcw-x35f · GitHub Advisory Database · CC BY 4.0
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