Cyber Resilience

CVE-2026-23881

DoS in Kyverno ≤ 1.15.3

Public PoCDoS
Published
27 January 2026
Modified
02 February 2026
Patch / advisory
CVSS Score v3.1 7.7
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
EPSS Score 0.0053 42th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2026-23881 is a high-severity Allocation of Resources Without Limits or Throttling (CWE-770) vulnerability in Kyverno Kyverno. Its CVSS base score is 7.7 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Network Denial of Service (T1498); ranked at the 42th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to AC-10 (Concurrent Session Control) and SC-6 (Resource Availability) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2026-23881 is a vulnerability in Kyverno, a policy engine for cloud native platform engineering teams, affecting versions prior to 1.16.3 and 1.15.3. It stems from unbounded memory consumption (CWE-770) in Kyverno's policy engine, where users can craft policies that exponentially amplify string data through context variables, leading to denial of service. The issue carries a CVSS v3.1 base score of 7.7 (AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H) and was published on 2026-01-27.

Attackers require low privileges, specifically policy creation permissions (PR:L), to exploit the vulnerability remotely over the network (AV:N) with low complexity (AC:L) and no user interaction (UI:N). Exploitation changes scope (S:C) and achieves high-impact denial of service (A:H) by consuming excessive memory, potentially crashing the policy engine without affecting confidentiality or integrity.

Kyverno addresses the vulnerability with patches in versions 1.16.3 and 1.15.3. Mitigation details are available in the GitHub security advisory (GHSA-r2rj-wwm5-x6mq) and the corresponding fix commits (7a651be3a8c78dcabfbf4178b8d89026bf3b850f and f5617f60920568a301740485472bf704892175b7).

EU & UK References

Vulnerability Data

Kyverno is a policy engine designed for cloud native platform engineering teams. Versions prior to 1.16.3 and 1.15.3 have unbounded memory consumption in Kyverno's policy engine that allows users with policy creation privileges to cause denial of service by crafting…

more

policies that exponentially amplify string data through context variables. Versions 1.16.3 and 1.15.3 contain a patch for the vulnerability.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1498 Network Denial of Service Impact
Adversaries may perform Network Denial of Service (DoS) attacks to degrade or block the availability of targeted resources to users.
T1499 Endpoint Denial of Service Impact
Adversaries may perform Endpoint Denial of Service (DoS) attacks to degrade or block the availability of services to users.
T1499.003 Application Exhaustion Flood Impact
Adversaries may target resource intensive features of applications to cause a denial of service (DoS), denying availability to those applications.
T1498.001 Direct Network Flood Impact
Adversaries may attempt to cause a denial of service (DoS) by directly sending a high-volume of network traffic to a target.
T1498.002 Reflection Amplification Impact
Adversaries may attempt to cause a denial of service (DoS) by reflecting a high-volume of network traffic to a target.
T1499.001 OS Exhaustion Flood Impact
Adversaries may launch a denial of service (DoS) attack targeting an endpoint's operating system (OS).
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-41485Same product: Kyverno Kyverno
CVE-2025-47281Same product: Kyverno Kyverno
CVE-2026-41323Same product: Kyverno Kyverno
CVE-2026-40868Same product: Kyverno Kyverno
CVE-2026-22039Same product: Kyverno Kyverno
CVE-2023-47630Same product: Kyverno Kyverno
CVE-2025-46342Same product: Kyverno Kyverno
CVE-2026-41068Same product: Kyverno Kyverno
CVE-2025-29778Same product: Kyverno Kyverno
CVE-2026-4789Same product: Kyverno Kyverno

Affected Assets

kyverno
kyverno
≤ 1.15.3 · 1.16.0 — 1.16.3

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 5 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V15.4.4

Mitigating Controls (NIST 800-53 r5) AI

Directly enforces a hard limit on concurrent sessions, structurally preventing unbounded resource allocation.

Requires explicit allocation of resources by priority or quota, directly stopping unlimited allocation.

Imposes a limit on consecutive invalid attempts, preventing one specific class of unbounded resource consumption.

Reduces impact of resulting DoS events without preventing the underlying lack of allocation limits.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.IR-04 mostly match
degrades

Monitoring capacity and taking action to maintain availability directly reduces unchecked resource allocation.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

finds

Baseline comparison of CPU, memory and bandwidth usage helps surface uncontrolled resource allocations before they cause service degradation.

prevents

Capacity projections and elasticity measures ensure that allocation requests are bounded and can be throttled, reducing the window in which an attacker can force unbounded resource reservations.

mitigates

Defining retention periods and deletion schedules for backup copies prevents indefinite accumulation of data on storage media without corresponding resource-management controls.

mitigates

Architectural redundancy and automatic failover limit the impact of an attacker who forces excessive allocations, because spare capacity can absorb the load until the primary instance recovers.

none

Documented incident response procedures that include activation of continuity plans and controlled recovery help ensure that resource consumption triggered by an incident is bounded and managed rather than left unbounded.

mitigates

Mandating tested continuity procedures that preserve or replace resource-limiting controls prevents an attacker from exploiting the absence of throttling mechanisms during an outage.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Oracle Linux 8 (2 rules)
  • V-248552 OL 8 must be configured so that all network connections associated with SSH traffic terminate after becoming unresponsive. prevents CWE-770
  • V-248553 OL 8 must be configured so that all network connections associated with SSH traffic are terminated after 10 minutes of becoming unresponsive. prevents CWE-770
Oracle Linux 9 (2 rules)
  • V-271710 OL 9 must be configured so that all network connections associated with SSH traffic are terminated after 10 minutes of becoming unresponsive. prevents CWE-770
  • V-271709 OL 9 must be configured so that all network connections associated with SSH traffic terminate after becoming unresponsive. prevents CWE-770
RHEL 8 (1 rule)
  • V-230244 RHEL 8 must be configured so that all network connections associated with SSH traffic terminate after becoming unresponsive. prevents CWE-770

References