CVE-2026-55075: Coder account takeover via OIDC authentication bypass

CVE-2026-55075 · Severity: high · CVSS 7.4 · Published 2026-07-07

Coder, a platform for managing remote development environments, contains a security flaw in its login system that could allow an attacker to take over user accounts. By exploiting how the system verifies email addresses and links them to external login providers (like Google or Microsoft), an attacker could trick the platform into granting them access to a victim's workspace. This could lead to the theft of sensitive source code or unauthorized access to corporate development infrastructure.

Technologies: Coder, github.com/coder/coder (Go), github.com/coder/coder/v2 (Go). Vendors: Coder, Go.

Quick answers

Is CVE-2026-55075 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-55075 being exploited in the wild.
How severe is CVE-2026-55075?
High severity, with a CVSS score of 7.4, published 7 July 2026.
Which products and versions are affected?
Coder < 2.29.17, >= 2.30.0 < 2.32.7, >= 2.33.0 < 2.33.8, >= 2.34.0 < 2.34.2, < 2.29.17, >= 2.30.0, < 2.32.7, >= 2.33.0, < 2.33.8, >= 2.34.0, < 2.34.2; github.com/coder/coder (Go) SEMVER:introduced=0; github.com/coder/coder/v2 (Go) SEMVER:introduced=0,fixed=2.29.17,introduced=2.30.0,fixed=2.32.7,introduced=2.33.0,fixed=2.33.8,introduced=2.34.0,fixed=2.34.2, SEMVER:introduced=2.34.0,fixed=2.34.2.
Is there a fix for CVE-2026-55075?
Yes. github.com/coder/coder/v2 (Go): upgrade to 2.34.2 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-55075 attacked?
It is attacked over the network, in a network appliance.
Am I affected by CVE-2026-55075?
Check whether you run Coder, github.com/coder/coder (Go) or github.com/coder/coder/v2 (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • github.com/coder/coder/v2 (Go): upgrade to 2.34.2 or later
    go get github.com/coder/coder/v2@v2.34.2

Technical details

Two vulnerabilities in Coder's OIDC implementation can be chained to achieve account takeover. First, the `email_verified` claim check used a Go type assertion that failed silently if the claim was a string, number, or absent, defaulting to 'verified'. Second, the `findLinkedUser` function performed an email-based lookup fallback for all logins without verifying if the email was already linked to a different Identity Provider (IdP) subject. An attacker can register a victim's email at an IdP and bypass the `linked_id` check to match the victim's Coder account. The fix restricts email fallback to first-time linking and implements fail-closed logic for the `email_verified` claim.

Affected products

  • Coder Coder < 2.29.17, >= 2.30.0 < 2.32.7, >= 2.33.0 < 2.33.8, >= 2.34.0 < 2.34.2

Identifiers

  • CVE-2026-55075
  • GHSA-9r87-mvcw-x35f
  • GO-2026-5908

Timeline

  • 2026-05-27: other: Internal fixes submitted via pull requests
  • 2026-06-12: patched: Security hardening releases published
  • 2026-07-07: disclosed: CVE published to NVD

References

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