CVE-2026-41187: Calico's apiserver wraps tier-scoped resources so that every operation runs through AuthorizeTierOperation, bu

Routine

MEDIUM 6.5UPGRADE

CVE-2026-41187 is a medium-severity flaw (CVSS 6.5) affecting calico. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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.

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	6.5 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.4% (top 67%)
CISA exploited list	No
Weakness	CWE-285, CWE-863
Published	2026-07-30
Last modified	2026-08-08

Publisher (CNA): Tigera, Inc. · Vendor: tigera

Last updated 2026-08-08 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-07-30 15:16 UTCPublished CVE record published
2026-08-08 01:16 UTCUpdated Record last modified

tigera calico UPGRADE

Affected: < 3.21.7 · < 3.31.6 · <= 22.4.0 · >= 3.22.0 and < 3.22.4 · >= 3.32.0 and < 3.32.1

Fixed in: 3.21.7, 3.22.4, 3.31.6, 3.32.1

Safe to downgrade to: a release before 3.22.0

1. Check installed version

apt-cache policy calico || rpm -q calico || calico --version

2. UPGRADE to 3.21.7 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade calico

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade calico

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 3.22.0 (Debian / Ubuntu)

apt-cache madison calico sudo apt install calico=<VERSION_BEFORE_3.22.0> sudo apt-mark hold calico

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list calico sudo dnf downgrade calico-<VERSION_BEFORE_3.22.0> sudo dnf versionlock add calico

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-41187?

calico: upgrade to 3.21.7, 3.22.4, 3.31.6, 3.32.1. Exact commands for each OS are on this page.

Is CVE-2026-41187 being exploited?

CVE-2026-41187 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-41187 affect?

CVE-2026-41187 affects calico. Severity is medium (CVSS 6.5). 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 request

How urgent is CVE-2026-41187?

Priority 31/100. No elevated risk signals yet.

Related CVEs

CVE-2026-41184 MEDIUM 6.5 UPGRADE In Calico, the install-cni init container logs the rendered CNI configuration to standard output
CVE-2026-41186 HIGH 7.5 UPGRADE When Calico's shared debug server is enabled (disabled by default), the Calico kube-controllers and Goldmane c
CVE-2026-6540 HIGH 7.5 UPGRADE Calico's Application Layer Policy (disabled by default), which enforces HTTP rules through Dikastes, fails to

References

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