Vulnerability in github.com/projectcapsule/capsule (CVE-2026-65834)
Summary
Vulnerability in github.com/projectcapsule/capsule (CVE-2026-65834). Risk of unauthorized operations or information disclosure. Exploitable via ForbiddenAnnotations.Regex. Mitigation: upgrade to 0.13.8 or later.
Original description
The description as published by the source.
Summary
CapsuleConfiguration.Spec.NodeMetadata.ForbiddenLabels.Regex and ForbiddenAnnotations.Regex are never validated by any admission webhook. A Cluster Admin can persist a malformed regex to etcd without being blocked. Once stored, every Node CREATE, UPDATE, or PATCH request triggers regexp.MustCompile() in pkg/api/forbidden_list.go:36, which panics and crashes the node admission webhook — causing a cluster-wide Denial of Service for all Node operations.
Root cause
internal/webhook/tenant/validation/ contains dedicated regex validators for every Tenant regex field (hostname, storageclass, ingressclass, containerregistry, etc.). internal/webhook/cfg/ contains no regex validator at all — only owners.go, serviceaccount.go, and warnings.go.
The downstream consumer internal/webhook/node/user_metadata.go calls:
// line 131
matched = forbiddenLabels.RegexMatch(label)
// line 150
matched = forbiddenAnnotations.RegexMatch(annotation)
Which routes to pkg/api/forbidden_list.go:36:
func (in ForbiddenListSpec) RegexMatch(value string) (ok bool) {
if len(in.Regex) > 0 {
ok = regexp.MustCompile(in.Regex).MatchString(value) // ← panics on invalid regex
}
return ok
}
Unlike regexp.Compile, regexp.MustCompile panics instead of returning an error. Since no webhook validates the CapsuleConfiguration regex fields before storage, a malformed value reaches MustCompile on every Node admission reques…
Source: NIST National Vulnerability Database 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-2026-65834 has been found in github.com/projectcapsule/capsule.
Attackers can target a specific entry point like ForbiddenAnnotations.Regex over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 6.8/10.
What to do: upgrade github.com/projectcapsule/capsule to 0.13.8 or later.
If unsure, ask your IT team or search "github.com/projectcapsule/capsule CVE-2026-65834" on the vendor's site.
CVE-2026-65834 (github.com/projectcapsule/capsule) — CWE-20 / CVSS v3 6.8
Attack vector: remote (network-reachable) / no user interaction
Attack surface: ForbiddenAnnotations.Regex / CREATE / UPDATE / PATCH
Patched: 0.13.8 — apply immediately
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-20) exists in github.com/projectcapsule/capsule. Attackers reach the vulnerable code path via ForbiddenAnnotations.Regex.
Check the vendor advisory for the affected versions of github.com/projectcapsule/capsule. Attack surface: ForbiddenAnnotations.Regex / CREATE / UPDATE / PATCH.
Severity: Medium (CVSS 6.8/10). Risk of unauthorized operations or information disclosure.
Update to 0.13.8.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'github.com/projectcapsule/capsule' . 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/projectcapsule/capsule' . | 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/projectcapsule/capsuleを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade github.com/projectcapsule/capsule to 0.13.8ステージング環境で 0.13.8 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。
-
3Post-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 nvd.nist.gov
- package github.com
- web github.com
- web github.com
- web github.com