---
id: CVE-2026-55075
aliases:
  - GHSA-9r87-mvcw-x35f
title: >-
  Coder vulnerable to OIDC account takeover via email-based user matching and
  email_verified bypass
summary: >-
  Coder vulnerable to OIDC account takeover via email-based user matching and
  email_verified bypass
severity: high
cvss: 7.4
cwe:
  - CWE-287
  - CWE-289
vendor: coder
product: github.com/coder/coder/v2
ecosystem: go
affected:
  - 'github.com/coder/coder/v2 >= 2.34.0, < 2.34.2'
  - 'github.com/coder/coder/v2 >= 2.33.0, < 2.33.8'
  - 'github.com/coder/coder/v2 >= 2.30.0, < 2.32.7'
  - github.com/coder/coder/v2 < 2.29.17
patched:
  - github.com/coder/coder/v2 2.34.2
  - github.com/coder/coder/v2 2.33.8
  - github.com/coder/coder/v2 2.32.7
  - github.com/coder/coder/v2 2.29.17
published: '2026-07-06'
updated: '2026-07-06'
source: GHSA
sourceUrl: 'https://github.com/advisories/GHSA-9r87-mvcw-x35f'
references:
  - url: 'https://github.com/coder/coder/security/advisories/GHSA-9r87-mvcw-x35f'
  - url: 'https://github.com/coder/coder/pull/25712'
  - url: 'https://github.com/coder/coder/pull/25713'
  - url: 'https://github.com/advisories/GHSA-9r87-mvcw-x35f'
tags:
  - ghsa
  - go
ingestedAt: '2026-07-06T21:45:52.977Z'
epss: 0.00479
epssPercentile: 0.38637
---

## Overview

### Summary

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.

### Impact

An attacker who could authenticate at the configured OIDC provider with an email matching a victim's Coder account could log in as that victim and gain full access to their workspaces, templates and resources. This required OIDC authentication, attacker control of a matching email at the IdP and a victim account not yet linked to a different IdP subject.

### Patches

The fix 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.

The fix was backported to all supported release lines:

| Release line | Patched version |
|---|---|
| 2.34 | [v2.34.2](https://github.com/coder/coder/releases/tag/v2.34.2) |
| 2.33 | [v2.33.8](https://github.com/coder/coder/releases/tag/v2.33.8) |
| 2.32 | [v2.32.7](https://github.com/coder/coder/releases/tag/v2.32.7) |
| 2.29 (ESR) | [v2.29.17](https://github.com/coder/coder/releases/tag/v2.29.17) |

### Workarounds

Configure the OIDC provider to disallow self-registration or to require email verification before issuing tokens.

### Resources

- Fix: #25712, #25713

### Credits

Coder would like to thank Anthropic's Security Team (ANT-2026-22450) for independently disclosing this issue!

## Affected packages

- `github.com/coder/coder/v2 >= 2.34.0, < 2.34.2`
- `github.com/coder/coder/v2 >= 2.33.0, < 2.33.8`
- `github.com/coder/coder/v2 >= 2.30.0, < 2.32.7`
- `github.com/coder/coder/v2 < 2.29.17`

## Remediation

Upgrade to a patched release:

- `github.com/coder/coder/v2 2.34.2`
- `github.com/coder/coder/v2 2.33.8`
- `github.com/coder/coder/v2 2.32.7`
- `github.com/coder/coder/v2 2.29.17`