| Description | Severity | Notes |
|---|---|---|
Calico Tier Authorization Bypass via DeleteCollectionReference: TTA-2026-006, CVE-2026-41187 Date published: July 30, 2026 |
Medium | N/A |
Summary
Calico’s apiserver wraps tier-scoped resources so that every operation runs through AuthorizeTierOperation, but the Delete override on NetworkPolicy, GlobalNetworkPolicy, and their staged variants is not invoked for DeleteCollection requests. A user holding the deletecollection verb or wildcard verbs on tier-scoped policy resources can bulk-delete policies in tiers they otherwise have no rights on, breaking the tier authorization boundary.
Severity
CVSSv4.0: 6.2 (Medium)
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:L/VI:L/VA:L/SC:N/SI:L/SA:H
Exploitation requires an authenticated user with deletecollection (or wildcard) verbs on tier-scoped policy resources. The bypass is an integrity/availability issue: an attacker can destroy policy enforcement in tiers they are not authorized to manage.
References
Weakness Enumeration
CWE-285: Improper Authorization
CWE-863: Incorrect Authorization
Indicators of Impact/Compromise
DeleteCollectionrequests against NetworkPolicy / GlobalNetworkPolicy (or staged variants) affecting tiers a subject is not authorized to manage.- Unexpected disappearance of policies performed by a subject without per-tier authorization.
Workaround/Mitigation
Do not grant the deletecollection verb, or wildcard ["*"] verbs, on tier-scoped policy resources to users who should not be able to delete policies across tiers. Upgrade to a fixed version.
Affected Releases
- Calico Open Source
- All versions prior to v3.31.6
- v3.32.0 through prior to v3.32.1
- Calico Enterprise
- All versions prior to v3.21.7
- v3.22.0 through prior to v3.22.5
- Calico Cloud
- All versions prior to v22.4.0
Fixed Versions
- Calico Open Source
- v3.31.6
- v3.32.1
- Calico Enterprise
- v3.21.7
- v3.22.5
- Calico Cloud
- v22.4.0 and later
Acknowledgments
We would like to thank the following individuals:
- Behnam Shobiri — Finder
- Mazdak Nasab — Remediation Developer
- Anthony Tam — Remediation Reviewer
- Matt Dupre — Remediation Reviewer
