CVE-2026-55075 Coder vulnerability
Coder allows organizations to provision remote development environments via Terraform. Prior to versions 2.29.17, 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 2.29.17, 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.
Quick answer
Coder should be reviewed and updated if it matches the affected versions. The recommended fix is to apply the vendor-supported patched version or the mitigation steps below, then retest the public website with Fixnx.
Who is affected
Affected versions
- >=2.34.0 <2.34.2
- >=2.33.0 <2.33.8
- >=2.30.0 <2.32.7
- <2.29.17
Fixed versions
- 2.29.17
- 2.32.7
- 2.33.8
- 2.34.2
How to fix it
CVE-2026-55075 affects Coder remote development deployments where two OIDC login flaws can chain into account takeover through unsafe email-based matching and weak email_verified enforcement. Prioritize internet-facing, shared, or multi-tenant Coder environments because compromise can affect developer workspaces, identity flows, tokens, or control-plane availability depending on the issue. Upgrade to Coder 2.29.17, 2.32.7, 2.33.8, and 2.34.2, or a later supported release on the relevant branch, because those are the vendor-supported patched versions. Configure the OIDC provider to disallow self-registration or require verified email before token issuance until the patched Coder release is deployed.
- Inventory all Coder servers, workspace proxies, provisioner daemons, AI Bridge components, templates, and CLI installations across production, staging, and developer environments.
- Identify affected Coder versions and compare every deployment with the fixed releases for CVE-2026-55075: 2.29.17, 2.32.7, 2.33.8, and 2.34.2.
- Upgrade Coder servers and related components to the patched release for the installed branch, then roll updated CLI or automation binaries where they are part of the affected workflow.
- Configure the OIDC provider to disallow self-registration or require verified email before token issuance until the patched Coder release is deployed.
- Review Coder role bindings, OIDC settings, API keys, template parameters, provisioner access, workspace app exposure, and reverse proxy rules for unnecessary trust or public reachability.
- Review Coder audit logs, reverse proxy logs, provisioner logs, and workspace events for suspicious requests matching the affected endpoint or workflow.
- If exploitation or credential exposure is suspected, revoke affected sessions, rotate API keys and workspace tokens, preserve audit evidence, and rebuild workspaces or hosts whose integrity cannot be trusted.
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Verify the fix
- Confirm every affected Coder component reports a patched version for CVE-2026-55075: 2.29.17, 2.32.7, 2.33.8, and 2.34.2, or a later supported release.
- Confirm OIDC email fallback is limited to safe first-time or legacy linking and email_verified defaults to false for unexpected values.
- Confirm temporary restrictions, role changes, OIDC settings, proxy ACLs, and API-key revocations match the intended least-privilege policy.
- Review logs after patching to confirm exploit attempts are blocked or fail safely without exposing credentials, internal network details, or control-plane availability.
- Document patched versions, configuration changes, remaining exceptions, and evidence, then rerun Fixnx or the relevant vulnerability scan where applicable.
Related categories
Trusted references
FAQ
What is affected by CVE-2026-55075?
Coder versions listed as affected should be reviewed: >=2.34.0 <2.34.2, >=2.33.0 <2.33.8, >=2.30.0 <2.32.7, <2.29.17.
What should I fix first?
Start with internet-facing sites, admin panels, login flows, plugins, themes, modules, packages, and systems that process user-controlled input or sensitive data.
How do I confirm the fix worked?
Apply the patched version or mitigation, clear caches where relevant, retest the affected workflow, and run a new Fixnx scan to verify public website exposure signals.
How are Fixnx security risk categories chosen?
Fixnx keeps one canonical risk page and assigns only broad, relevant categories such as ecosystem, technology area, or vulnerability class.