CVE-2026-65835
MEDIUMCVE-2026-65835 is a medium-severity (CVSS 6.6) Improper Privilege Management vulnerability in github.com/projectcapsule/capsule. O3 Security confirms whether CVE-2026-65835 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Capsule: Incomplete fix of CVE-2026-22872: TenantResource RawItems and Generators still allow cluster-scoped resource creation (cross-tenant privilege escalation)
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-65835.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2026-65835 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 372,613 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
github.com/projectcapsule/capsuleReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Capsule is a multi-tenancy and policy-based framework for Kubernetes. From 0.13.0 until 0.13.8, after the incomplete CVE-2026-22872 fix, TenantResource RawItems and Generators in internal/controllers/resources/collect.go, including handleRawItem and handleGeneratorItem, did not apply the ResourceReference.LoadResources and IsNamespacedGVK cluster-scoped resource rejection guard used by NamespacedItems, allowing a Tenant Owner to create cluster-scoped resources such as ClusterRole or ValidatingWebhookConfiguration through the cluster-admin controller client. This issue is fixed in version 0.13.8.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/projectcapsule/capsule | ≥ 0.13.0&&< 0.13.8 | 0.13.8 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/projectcapsule/capsule. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update github.com/projectcapsule/capsule to 0.13.8 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-65835 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-65835 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-65835. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-65835 in your dependencies?
O3 detects CVE-2026-65835 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.