CVE-2026-55636

MEDIUMPre-NVD 5.75.7
EchelonGraph scoreLOW confidence

This medium-severity CVE scores 5.7 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: secondary
5.7EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.7Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

Capsule is a multi-tenancy and policy-based framework for Kubernetes. From 0.13.0 until 0.13.6, charts/capsule/templates/configuration.yaml configures the validating webhook with namespace/finalize instead of the Kubernetes resource name namespaces/finalize. A user with namespaces/finalize RBAC can send a PUT request to /api/v1/namespaces/{namespace}/finalize, and the singular rule never matches the plural resource, so the validating webhook is not invoked and the user can change the namespace tenant label. matchPolicy: Equivalent does not compensate because it handles API group and version equivalence rather than resource-name errors. This vulnerability is fixed in 0.13.6.

CVSS v3
5.7
EG Score
5.7(low)
EG Risk
26(Track)
EG Risk 26/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity57% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
20%
KEV
Not listed

Published

June 17, 2026

Last Modified

September 15, 2026

Advisory Details (4)

Auto-updated Sep 15, 2026
🔬 Proof of concept available. Patch available. Sources: github, github_pr, github_commit, github_release.
github_release Patch Available

v0.13.6

Patch available: projectcapsule/capsule v0.13.6

https://github.com/projectcapsule/capsule/releases/tag/v0.13.6
github_commit

commit af2f37793e78 (projectcapsule/capsule)

Fix landed in projectcapsule/capsule commit af2f37793e78 — awaiting tagged release

https://github.com/projectcapsule/capsule/commit/af2f37793e789b2301da8ed8dfb52ab60affebb6
github_pr

fix: add serviceaccount validation for tenantowners and tenants

Fix merged in projectcapsule/capsule PR #1966 on 2026-06-17 — awaiting tagged release

https://github.com/projectcapsule/capsule/pull/1966
github Patch Available🟡 PoC Available

Incomplete fix of CVE-2026-30963: singular/plural typo leaves namespaces/finalize unprotected · Advisory · projectcapsule/capsule · GitHub

https://github.com/projectcapsule/capsule/security/advisories/GHSA-gwxr-7h77-7777

Vendor Advisories for CVE-2026-55636(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(1 across 1 ecosystem)
Go(1)
PackageVulnerable rangeFixed inDependents
github.com/projectcapsule/capsule—0.13.6—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 6× in last 7d / 6× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-09-18 19:28 UTCEPSS rescore
  2. 2026-09-17 19:31 UTCEPSS rescore
  3. 2026-09-16 14:08 UTCEPSS rescore
  4. 2026-09-15 19:41 UTCEG score recompute
  5. 2026-09-15 18:26 UTCEG score recompute
  6. 2026-09-15 16:36 UTCEG score recompute
  7. 2026-07-31 08:15 UTCEG score recompute
  8. 2026-07-26 19:04 UTCEG score recompute
  9. 2026-07-23 03:20 UTCEG score recompute
  10. 2026-06-17 18:46 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-55636?
CVE-2026-55636 is a medium vulnerability published on June 17, 2026. Capsule is a multi-tenancy and policy-based framework for Kubernetes. From 0.13.0 until 0.13.6, charts/capsule/templates/configuration.yaml configures the validating webhook with namespace/finalize instead of the Kubernetes resource name namespaces/finalize. A user with namespaces/finalize RBAC can…
When was CVE-2026-55636 disclosed?
CVE-2026-55636 was first published in the National Vulnerability Database on June 17, 2026, with the most recent update on September 15, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-55636 actively exploited?
CVE-2026-55636 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 79.6% of all scored CVEs.
What is the CVSS score of CVE-2026-55636?
CVE-2026-55636 has a CVSS v3 base score of 5.7 (NVD). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-55636?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-55636, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-55636

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