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Fencer Vulns
high 7.1

CVE-2026-61672 json

Capsule: Tenant owner bypasses Capsule's forbidden namespace/service/node label and annotation enforcement

published 2026-09-18 51 d ago modified 2026-09-28 41 d ago also GHSA-gjw4-3v3v-rqxg , GO-2026-6520 , EUVD-2026-83164

cvss
7.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 26%
public exploits
0
none known

Summary

Capsule is a multi-tenancy and policy-based framework for Kubernetes. Prior to 0.13.7, ForbiddenListSpec.ExactMatch in pkg/api/forbidden_list.go sorts denied metadata keys case-insensitively and then uses sort.SearchStrings, which assumes byte-order sorting. When an administrator's forbidden list mixes capitalized and lowercase keys or otherwise has different case-insensitive and byte ordering, the binary search can return false for a key that is present. An authenticated tenant owner can then pass the missed key through api.ValidateForbidden and bypass configured namespace, Service, or delegated node metadata restrictions, potentially influencing cluster policies, network exposure, or scheduling outside the tenant boundary. Uniformly lowercase lists whose two orderings coincide are not affected. This issue is fixed in version 0.13.7.

Patch / fix

  • go github.com/projectcapsule/capsule 0.13.7

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
47 d ago

Exploit prediction

0.33% chance of exploitation in the next 30 days, higher than 26% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/projectcapsule/capsule/security/advisories/GHSA-gjw4-3v3v-rqxg referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 7.1 CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:H/A:N
GitHub 3.1 7.1 CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:H/A:N

Affected packages

ecosystem package affected fixed in
go github.com/projectcapsule/capsule
<0.13.7
0.13.7

Affected products

  • projectcapsule capsule

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.