Vulnerability in github.com/coder/coder/v2 (CVE-2026-55432)
Summary
Vulnerability in github.com/coder/coder/v2 (CVE-2026-55432). Risk of unauthorized operations or information disclosure. Exploitable via CreateSubAgent. 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, the CreateSubAgent RPC did not validate a requested app sharing level against the template's MaxPortSharingLevel before persisting workspace apps, letting a workspace owner exceed the administrator's configured maximum. Exploitation requires the ability to register sub-agent apps in a workspace the attacker controls. The fix in versions 2.29.7, 2.32.7, 2.33.8, and 2.34.2clamps the sub-agent app sharing level to the template's MaxPortSharingLevel. As a workaround, disable wildcard app hostnames (CODER_WILDCARD_ACCESS_URL) to block subdomain-based app routing.
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-2026-55432 has been found in github.com/coder/coder/v2.
Attackers can target a specific entry point like CreateSubAgent 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 2.29.17 or later.
If unsure, ask your IT team or search "github.com/coder/coder/v2 CVE-2026-55432" on the vendor's site.
CVE-2026-55432 (github.com/coder/coder/v2) — CWE-862 / CVSS v3 5.4
Attack vector: remote (network-reachable) / no user interaction
Attack surface: CreateSubAgent / MaxPortSharingLevel / PUBLIC / owner
Patched: 2.29.17 — apply immediately
Workaround: Disable wildcard app hostnames (CODER_WILDCARD_ACCESS_URL) to block subdomain-based app routing.
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.
A vulnerability (CWE-862) exists in github.com/coder/coder/v2. Attackers reach the vulnerable code path via CreateSubAgent.
Check the vendor advisory for the affected versions of github.com/coder/coder/v2. Attack surface: CreateSubAgent / MaxPortSharingLevel / PUBLIC / owner.
Severity: Medium (CVSS 5.4/10). Risk of unauthorized operations or information disclosure.
Update to 2.29.17.
Workaround: Disable wildcard app hostnames (CODER_WILDCARD_ACCESS_URL) to block subdomain-based app routing.
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
-
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
Disable wildcard app hostnames (`CODER_WILDCARD_ACCESS_URL`) to block subdomain-based app routing.パッチが適用されるまでの応急処置として、Disable wildcard app hostnames (
CODER_WILDCARD_ACCESS_URL) to block subdomain-based app routing. を実施。回避策の副作用 (機能低下) を確認した上で。 -
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。
-
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
- web github.com
- web github.com
- web github.com
- web github.com
- web github.com