CVE-2026-54462: DoS (CVSS 6.5)

Description

Knative pkg provides common packages shared across Knative repositories. Prior to 0.0.0-20260531000007-52dbd5ece63f, the knative.dev/pkg/webhook admissionHandler in webhook/admission.go decodes an attacker-supplied AdmissionReview through json.NewDecoder(io.TeeReader(r.Body, &bodyBuffer)) under an http.HandlerFunc without an http.MaxBytesReader or equivalent body-size limit. A pod-network client can send one oversized POST to an admission webhook, causing the decoder and bodyBuffer to retain amplified copies of the request until the controller pod exhausts memory and is OOM-killed. Every downstream consumer using the shared webhook server inherits the vulnerable behavior, including Knative, Tekton, KEDA, Sigstore policy-controller, and Kpack. For consumers configured with failurePolicy=Fail, loss of the controller can interrupt admission; with failurePolicy=Ignore, the affected webhook is unavailable while other admissions continue. This issue is fixed in version 0.0.0-20260531000007-52dbd5ece63f.

Is your site exposed to CVE-2026-54462?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

6.5

MEDIUM

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

EPSS — Exploit Prediction

0.0038

Probability of exploitation

0.32%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-770 CWE-770

References

Other References

https://github.com/knative/pkg/commit/52dbd5ece63fe6d2d340ecbebec160550f460818 https://github.com/knative/pkg/pull/3363 https://github.com/knative/pkg/security/advisories/GHSA-2hw4-c9m4-f2fj

Frequently Asked Questions

What is CVE-2026-54462? +

Knative pkg provides common packages shared across Knative repositories. Prior to 0.0.0-20260531000007-52dbd5ece63f, the knative.dev/pkg/webhook admissionHandler in webhook/admission.go decodes an attacker-supplied AdmissionReview through json.NewDecoder(io.TeeReader(r.Body, &bodyBuffer)) under an http.HandlerFunc without an http.MaxBytesReader or equivalent body-size limit. A pod-network client can send one oversized POST to an admission webhook, causing the decoder and bodyBuffer to retain amplified copies of the request until the controller pod exhausts memory and is OOM-killed. Every downstream consumer using the shared webhook server inherits the vulnerable behavior, including Knative, Tekton, KEDA, Sigstore policy-controller, and Kpack. For consumers configured with failurePolicy=Fail, loss of the controller can interrupt admission; with failurePolicy=Ignore, the affected webhook is unavailable while other admissions continue. This issue is fixed in version 0.0.0-20260531000007-52dbd5ece63f. It has a CVSS v3.1 base score of 6.5 (MEDIUM).

How severe is CVE-2026-54462? +

CVE-2026-54462 has a CVSS v3.1 score of 6.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0038, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-54462? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2026-39313

mcp-framework is a framework for building Model Context Protocol (MCP) servers. In versions 0.2.21 and below, the readRequestBody() function in …

CVE-2026-35469

spdystream is a Go library for multiplexing streams over SPDY connections. In versions 0.5.0 and below, the SPDY/3 frame parser …

CVE-2026-104817

Misskey is an open source, federated social media platform. From 12.112.1 until 2026.7.0, the unauthenticated fetch-rss API lacks rate limiting …

CVE-2026-75956

Joomla Extension - cmsjunkie.com - DOS vector in pagination parameter handling in J-BusinessDirectory < 6.2.3 - Pagination values were not …

CVE-2026-39803

Allocation of Resources Without Limits or Throttling vulnerability in mtrudel bandit allows unauthenticated remote denial of service via memory exhaustion. …

CVE-2026-39804

Allocation of Resources Without Limits or Throttling vulnerability in mtrudel bandit allows unauthenticated remote denial of service via memory exhaustion …

CVE-2026-54462