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NVD / CVE Program· CNA GitHub_M

CVE-2023-42816: Denial of service from malicious signature in kyverno

Noroxi assessment

Priority: Monitor (action score 21/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.45% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. No account or password is required. A user must open a link or visit a page. Special conditions such as timing or configuration are required.
  • Fixed version: github.com/kyverno/kyverno (Go) 1.5.0-rc1.0.20230918070231-fec2992e3f9f.

Low priority for now. Upgrade to github.com/kyverno/kyverno (Go) 1.5.0-rc1.0.20230918070231-fec2992e3f9f or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

Kyverno is a policy engine designed for Kubernetes. A security vulnerability was found in Kyverno where an attacker could cause denial of service of Kyverno. The vulnerability was in Kyvernos Notary verifier. An attacker would need control over the registry from which Kyverno would fetch signatures. With such a position, the attacker could return a malicious response to Kyverno, when Kyverno would send a request to the registry. The malicious response would cause denial of service of Kyverno, such that other users' admission requests would be blocked from being processed. This is a vulnerability in a new component released in v1.11.0. The only users affected by this are those that have been building Kyverno from source at the main branch which is not encouraged. Users consuming official Kyverno releases are not affected. There are no known cases of this vulnerability being exploited in the wild.

MediumCVSS 5.3 · v3.1—No exploit Fix available
Published
Nov 13, 2023
Updated
Jun 17, 2026
EPSS
0.4% · 39th percentile

Report tools

JSON

Action score

21

Monitor

Low priority for now.

CVSS
21 / 40 · 5.3 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.4%

CNA vs NVD score

NVD
5.3
CNA · GitHub_M
6.1
0.8 point gap

CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:N/I:N/A:H

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

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When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
nirmatakyverno

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • nirmata kyverno1.11.0

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

  • kyverno kyverno

    • >= 80d139bb5d1d9d7e907abe851b97dc73821a5be2, < fec2992e3f9fcd6b9c62267522c09b182e7df73baffected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Gogithub.com/kyverno/kyvernofrom 1.5.0-rc1.0.20230601080528-80d139bb5d1d · before 1.5.0-rc1.0.20230918070231-fec2992e3f9f1.5.0-rc1.0.20230918070231-fec2992e3f9f

Same product

nirmata: all records

Other highest-scoring records for the same primary product.

  • CVE-2023-33191kyverno seccomp control can be circumvented
    35Monitor
  • CVE-2024-48921Kyverno's PolicyException objects can be created in any namespace by default
    34Monitor
  • CVE-2023-34091Kyverno resource with a deletionTimestamp may allow policy circumvention
    26Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2023-42813Nov 13, 2023 · Denial of service from malicious manifest in kyverno
    21Monitor
  • ← EarlierCVE-2023-42814Nov 13, 2023 · Denial of service from malicious image manifest in kyverno
    21Monitor
  • ← EarlierCVE-2023-42815Nov 13, 2023 · Denial of service from malicious image manifest in kyverno
    21Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Go:github.com/kyverno/kyverno1.5.0-rc1.0.20230918070231-fec2992e3f9fPackage registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • A user must open a link or visit a page.
  • Special conditions such as timing or configuration are required.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
High
Privileges required
None
User interaction
Required
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-345 · Insufficient Verification of Data Authenticity

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:H

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (3 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records