CVE-2026-61794
Capsule: Malformed ForbiddenAnnotations.Regex can bypass Tenant validation and trigger namespace admission panic
- Published
- Updated
- Reserved
- Assigned by
- GitHub_M
Description
Capsule is a multi-tenancy and policy-based framework for Kubernetes. From 0.13.0 until 0.13.7, the Tenant update validation in internal/webhook/tenant/validation/forbidden_annotations_regex.go compiles ForbiddenLabels.Regex for both the labels and annotations checks instead of validating ForbiddenAnnotations.Regex. An administrator who can update a Tenant can therefore persist a malformed ForbiddenAnnotations.Regex while leaving the labels expression valid. Namespace creation or update later passes the stored expression through pkg/api/forbidden_list.go, where regexp.MustCompile can panic during forbidden metadata validation and deny namespace operations for the affected tenant. This issue is fixed in version 0.13.7.
Public exploit
A reference of the record is tagged as an exploit or proof of concept: anyone can try it against an unpatched system. CISA's SSVC rates its exploitation: a proof of concept is public.
- https://github.com/projectcapsule/capsule/security/advisories/GHSA-gxjc-74v5-3vx3 (opens in a new tab)x_refsource_CONFIRMexploit
Timeline
ID reserved
By GitHub_M
- 2 months later
· 2 months later
Published
- 4 days later
· 4 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | Medium6.8 | CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:H |
| NVDNVD · Deferred | 3.1 | Medium6.8 | CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.59% · top 52% of all CVEs (7 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.8.
Weakness
Affected products
- affected >= 0.13.0, < 0.13.7
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- Gogithub.com/projectcapsule/capsuleGHSA-gxjc-74v5-3vx3 (opens in a new tab)
References (4)
- https://github.com/projectcapsule/capsule/security/advisories/GHSA-gxjc-74v5-3vx3 (opens in a new tab)x_refsource_CONFIRMexploit
- https://github.com/projectcapsule/capsule/pull/1983 (opens in a new tab)x_refsource_MISC
- https://github.com/projectcapsule/capsule/commit/8d89d6865df6f41c7faa22fc9e807a57b01bfd0e (opens in a new tab)x_refsource_MISC
- https://github.com/projectcapsule/capsule/releases/tag/v0.13.7 (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-gxjc-74v5-3vx3 (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-61794)Record last updated .