CVERadar
HIGH · CVSS 4.0 8.5EPSS 0.23% (p14)Threat level 43

CVE-2026-122321: CVE-2026-122321: Kyverno 1.18.0 before 1.19.2 contains a signature verification bypass in verifyImages beca…

Unknown · Kyverno · NVD published 2026-11-05 · posted 2026-11-05 · last modified 2026-11-05

CVE-2026-122321 at a glance

CVE-2026-122321 is a high-severity TOCTOU Race vulnerability in Kyverno, with a CVSS 4.0 base score of 8.5. NVD published it on 2026-11-05 and classifies the weakness as CWE-367. FIRST EPSS puts the probability of exploitation activity in the next 30 days at 0.23% (percentile 13.5, scored 2026-11-05). NVD does not list a fixed version, so the vendor advisory is the reference for the fix. Its CVERadar threat level is 43/100.

What it is

Kyverno 1.18.0 before 1.19.2 contains a signature verification bypass in verifyImages because cached verification results are keyed by the image reference string (such as a tag) rather than bound to the verified digest, so cache hits skip signature and attestation checks. An attacker who can submit workloads and move a registry tag can warm the cache with a signed image, repoint the tag, and have Kyverno admit the workload and use mutateDigest to pin the unverified digest.

WeaknessCWE-367 definition
CVSS vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:H/VA:L/SC:L/SI:H/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X (source: VulnCheck)
ATT&CK tacticsn/a

No ATT&CK techniques could be mapped or inferred for this CVE yet.

Patches, mitigations and detection

Fixed versions

NVD does not list a fixed version for this CVE. Use the vendor advisory below.

Derived from the NVD CPE configuration (versionEndExcluding / versionEndIncluding). Always confirm with the vendor advisory.

Vendor advisories and patches

No vendor-tagged reference yet; see the full reference list.

Detection Generic guidance

    Response checklist Generic guidance

    1. Inventory: find every instance of the affected product and version (include internet-facing and forgotten ones).
    2. Patch or mitigate per the vendor advisory; if you cannot patch, remove internet exposure or apply the vendor workaround.
    3. Assume compromise if the system was exposed before patching: hunt for the indicators in the advisory and review logs back to the disclosure date.
    4. Rotate credentials and secrets stored on or used by the affected system if compromise cannot be ruled out.

    Sources