Categories
CVE-2026-55435 medium CVSS 5.4

Authorization Flaw in github.com/coder/coder/v2 (CVE-2026-55435)

Summary

Vulnerability in github.com/coder/coder/v2 (CVE-2026-55435). Risk of unauthorized operations or information disclosure. Exploitable via DELETE /api/v2/users/{user}/keys. Mitigation: upgrade to 2.32.7 or later.

Original description

The description as published by the source.

Summary

AI Bridge proxy endpoints authenticate via Server.IsAuthorized in coderd/aibridgedserver, which validates key format, expiry, secret and deleted or system users but does not check whether the account is suspended. Because suspension does not revoke existing API keys, a suspended user's unexpired token keeps working.

Note: Practical impact is limited to already-issued API keys of suspended users until those keys are deleted.

Impact

A suspended user with a previously issued long-lived token could continue calling AI Bridge LLM proxy endpoints, consuming paid provider resources billed to the deployment and, if injected MCP tools are enabled, invoking those tools. Access persists until the token expires, which may be months after suspension.

Patches

The fix makes AI Bridge authorization reject non-active users like the standard API key middleware. AI Bridge was introduced in v2.30.0. The v2.29 ESR line is not affected.

The fix is available in the following releases:

Release line Patched version
2.34 v2.34.2
2.33 v2.33.8
2.32 v2.32.7

Workarounds

On suspension, delete the user's API keys via DELETE /api/v2/users/{user}/keys.

Resources

  • Fix: #26173

Credits

Coder would like to thank Anthropic's Security Team (ANT-2026-22446) for i…

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-2026-55435 has been found in github.com/coder/coder/v2.
Attackers can target a specific entry point like DELETE /api/v2/users/{user}/keys over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 5.4/10.
What to do: upgrade github.com/coder/coder/v2 to 2.32.7 or later.
If unsure, ask your IT team or search "github.com/coder/coder/v2 CVE-2026-55435" on the vendor's site.

CVE-2026-55435 (github.com/coder/coder/v2) — CWE-863 / CVSS v3 5.4
Attack vector: remote (network-reachable) / no user interaction
Attack surface: DELETE /api/v2/users/{user}/keys / Server.IsAuthorized
Patched: 2.32.7 — apply immediately
Workaround: On suspension, delete the user's API keys via DELETE /api/v2/users/{user}/keys.
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.

❓ What is the problem

Incorrect authorization (CWE-863) exists in github.com/coder/coder/v2. Attackers reach the vulnerable code path via DELETE /api/v2/users/{user}/keys.

📍 Affected scope

Check the vendor advisory for the affected versions of github.com/coder/coder/v2. Attack surface: DELETE /api/v2/users/{user}/keys / Server.IsAuthorized.

🔥 Severity

Severity: Medium (CVSS 5.4/10). Risk of unauthorized operations or information disclosure.

🔧 How to fix

Update to 2.32.7.

🛡️ Workaround

Workaround: On suspension, delete the user's API keys via DELETE /api/v2/users/{user}/keys.

🔍 Detection

Search webserver/proxy logs for unusual DELETE /api/v2/users/{user}/keys requests with malformed payloads or SQL meta-characters. 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

  1. 1
    Identify 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。

  2. 2
    Hunt for indicators of compromise detect
    grep 'DELETE /api/v2/users/{user}/keys' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'

    アクセスログで DELETE /api/v2/users/{user}/keys への異常なリクエスト (不正な認証ヘッダ・SQLメタ文字)を過去 30〜90日分捜索。WAF/SIEM があれば該当パスのアラート発火履歴を確認。

  3. 3
    Apply temporary workaround mitigate
    On suspension, delete the user's API keys via `DELETE /api/v2/users/{user}/keys`.

    パッチが適用されるまでの応急処置として、On suspension, delete the user's API keys via DELETE /api/v2/users/{user}/keys. を実施。回避策の副作用 (機能低下) を確認した上で。

  4. 4
    Apply patch patch
    Upgrade github.com/coder/coder/v2 to 2.32.7

    ステージング環境で 2.32.7 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と、Step 2 で見つけた異常検知の続報チェックを含めること。

  5. 5
    Post-deployment verification verify
    Replay attack against DELETE /api/v2/users/{user}/keys on staging to confirm patch closes the vector

    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 Step 2 と同じログクエリでアラート再発が無いか継続監視。

Affected packages

go github.com/coder/coder/v2
[{"type":"SEMVER","events":[{"introduced":"2.30.0"},{"fixed":"2.32.7"}]}]
Go github.com/coder/coder
[{"type":"SEMVER","events":[{"introduced":"0"}]}]

References

We use cookies for analytics and ad measurement. This setting applies to all Game co., Ltd. sites. Details