Authentication Bypass in github.com/coder/coder/v2 (CVE-2026-55075)
Summary
Authentication bypass in github.com/coder/coder/v2 (CVE-2026-55075). Confidential information can be exposed externally. Exploitable via email_verified. Mitigation: upgrade to 2.29.17 or later.
Original description
The description as published by the source.
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.
Source: GitHub Security Advisories (Global) NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-55075 has been found in github.com/coder/coder/v2.
Attackers can target a specific entry point like email_verified over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 7.4/10.
What to do: upgrade github.com/coder/coder/v2 to 2.29.17 or later.
If unsure, ask your IT team or search "github.com/coder/coder/v2 CVE-2026-55075" on the vendor's site.
CVE-2026-55075 (github.com/coder/coder/v2) — CWE-287 / CVSS v3 7.4
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: email_verified / false
Patched: 2.29.17 — apply immediately
Workaround: Configure the OIDC provider to disallow self-registration or to require email verification before issuing tokens.
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Authentication bypass (CWE-287) exists in github.com/coder/coder/v2. Attackers reach the vulnerable code path via email_verified without authentication.
Check the vendor advisory for the affected versions of github.com/coder/coder/v2. Attack surface: email_verified / false.
Severity: High (CVSS 7.4/10). Confidential information can be exposed externally.
Update to 2.29.17.
Workaround: Configure the OIDC provider to disallow self-registration or to require email verification before issuing tokens.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'github.com/coder/coder/v2' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
grep -r 'github.com/coder/coder/v2' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
github.com/coder/coder/v2を grep し、稼働しているサービス・バージョンを把握する。 -
2Apply temporary workaround mitigate
Configure the OIDC provider to disallow self-registration or to require email verification before issuing tokens.パッチが適用されるまでの応急処置として、Configure the OIDC provider to disallow self-registration or to require email verification before issuing tokens. を実施。回避策の副作用 (機能低下) を確認した上で。
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3Apply patch patch
Upgrade github.com/coder/coder/v2 to 2.29.17ステージング環境で 2.29.17 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
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4Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory github.com
- advisory github.com
- advisory nvd.nist.gov
- package github.com
- patch github.com
- patch github.com
- web github.com
- web github.com
- web github.com
- web github.com
- web github.com