CVE-2026-40924: Tekton Pipelines DoS via unbounded memory allocation in HTTP resolver

CVE-2026-40924 · Severity: medium · CVSS 6.5 · Published 2026-04-21

Tekton Pipelines is a framework for creating continuous integration and delivery (CI/CD) systems on Kubernetes. A vulnerability in the component that fetches remote resources via HTTP allows a user with basic permissions to crash the entire resolution service for the cluster. By pointing the system at a malicious server that sends a massive amount of data, an attacker can exhaust the system's memory, causing a denial-of-service that prevents all users from running their pipelines.

Technologies: github.com/tektoncd/pipeline (Go), Linuxfoundation Tekton Pipelines, Tekton Pipelines. Vendors: Go, Linuxfoundation, Tekton.

Quick answers

Is CVE-2026-40924 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-40924 being exploited in the wild.
How severe is CVE-2026-40924?
Medium severity, with a CVSS score of 6.5, published 21 April 2026.
Which products and versions are affected?
github.com/tektoncd/pipeline (Go) <= 1.11.0, SEMVER:introduced=1.0.0,fixed=1.0.2,introduced=1.1.0,fixed=1.3.4,introduced=1.4.0,fixed=1.6.2,introduced=1.7.0,fixed=1.9.3,introduced=1.10.0,fixed=1.11.1, SEMVER:introduced=1.10.0,fixed=1.11.1; Tekton Pipelines >= 1.10.0, < 1.11.1; >= 1.0.0, < 1.0.2; >= 1.2.0, < 1.3.4; >= 1.4.0, < 1.6.2; >= 1.7.0, < 1.9.3.
Is there a fix for CVE-2026-40924?
Yes. github.com/tektoncd/pipeline (Go): upgrade to 1.11.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-40924 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-40924?
Check whether you run github.com/tektoncd/pipeline (Go), Linuxfoundation Tekton Pipelines or Tekton Pipelines at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • github.com/tektoncd/pipeline (Go): upgrade to 1.11.1 or later
    go get github.com/tektoncd/pipeline@v1.11.1

Technical details

The vulnerability exists in the HTTP resolver's FetchHttpResource function, which uses io.ReadAll(resp.Body) without a size limit. An attacker with 'create' permissions for TaskRuns or PipelineRuns can specify a URL pointing to a malicious HTTP server. If this server returns a response body larger than the memory limit of the tekton-pipelines-resolvers pod (typically 4 GiB) within the 1-minute request timeout, the pod will be OOM-killed by Kubernetes. Because all resolver types (Git, Hub, Bundle, Cluster, HTTP) share the same pod, this results in a cluster-wide denial of service for resource resolution. The issue is fixed in versions 1.0.2, 1.3.4, 1.6.2, 1.9.3, and 1.11.1 by implementing a 1 MiB response body limit.

Affected products

  • Tekton CD Tekton Pipelines >= 1.0.0, < 1.0.2; >= 1.1.0, < 1.3.4; >= 1.4.0, < 1.6.2; >= 1.7.0, < 1.9.3; >= 1.10.0, < 1.11.1

Identifiers

  • CVE-2026-40924
  • GHSA-m2cx-gpqf-qf74
  • GO-2026-5486

Timeline

  • 2026-04-21: disclosed
  • 2026-04-21: patched
  • 2026-04-21: advisory

References

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