🛡️ CVE-2026-55076 — coder

🟠 CVSS 8.0 — High ✅ No Known Exploit CWE-287 NVD
8.0
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

Coder's OIDC email_verified type coercion bypass enables account takeover via unverified email linking

Summary

Coder's OIDC callback checked email_verified with a direct Go bool type assertion. When an IdP returned the claim as a non-boolean (for example the string "false") or omitted it, the assertion failed open and the email was treated as verified. Combined with an unconditional email-based account fallback, this enabled account takeover.

Impact

An attacker who registered a victim's email at a compatible IdP without verifying it could log in via OIDC and be matched to the victim's existing Coder account, receiving a session for that account. No prior authentication to Coder was required and the result was full account takeover.

Patches

The fix coerces email_verified across bool, string and numeric types (fail-closed) and blocks the email fallback when the matched user already has a different linked IdP subject.

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

Ensure the IdP returns email_verified as a native JSON boolean. The email-fallback linking issue has no configuration workaround; upgrading is required.

Resources

  • Fix: #25712, #25713

Credits

Coder would like to thank Anthropic's Security Team (ANT-2026-22444) for independently disclosing this issue!

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is high, an attacker needs no privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality high, integrity high, availability none.

Weakness class

CVE-2026-55076 is classified as CWE-287: Improper Authentication. The identity of the caller is not established correctly, so an attacker can act as another user.

Affected software

CVE-2026-55076 is recorded against 3 packages.

  • coder (from 2.34.0 up to 2.34.2)
  • github.com/coder/coder
  • github.com/coder/coder/v2

Timeline and source

Published on 7 July 2026 and last revised on 8 July 2026. No public exploit is currently recorded for this entry. A vendor advisory or fix has been published. Record sourced from NVD.

References

github.com
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Details

Severity HIGH
CVSS Score 8.0
CVSS Vector CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
CWE CWE-287
Public Exploit ✅ No
Source NVD
Published 2026-07-07
Updated 2026-08-12
Modified 2026-07-08

Affected Packages

Software From version Fixed in
coder 2.34.0 2.34.2
github.com/coder/coder — —
github.com/coder/coder/v2 — —

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