CVE-2026-40924: Tekton Pipelines: HTTP Resolver Unbounded Response Body Read Enables Denial of Service via Memory Exhaustion

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-04-21 · updated 2026-10-26
Weakness: CWE-400

Description

Tekton Pipelines project provides k8s-style resources for declaring CI/CD-style pipelines. Starting in version 1.0.0 and prior to versions 1.0.2, 1.3.4, 1.6.2, 1.9.3, and 1.11.1, the HTTP resolver's FetchHttpResource function calls io.ReadAll(resp.Body) with no response body size limit. Any tenant with permission to create TaskRuns or PipelineRuns that reference the HTTP resolver can point it at an attacker-controlled HTTP server that returns a very large response body within the 1-minute timeout window, causing the tekton-pipelines-resolvers pod to be OOM-killed by Kubernetes. Because all resolver types (Git, Hub, Bundle, Cluster, HTTP) run in the same pod, crashing this pod denies resolution service to the entire cluster. Repeated exploitation causes a sustained crash loop. The same vulnerable code path is reached by both the deprecated pkg/resolution/resolver/http and the current pkg/remoteresolution/resolver/http implementations. Versions 1.0.2, 1.3.4, 1.6.2, 1.9.3, and 1.11.1 fix the issue.

Affected products

tektoncd pipeline: before 1.11.1 — fixed in 1.11.1

How to fix

Upgrade to a fixed version: tektoncd pipeline 1.11.1. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2026-40924 or the next vulnerability affects your stack