CVE-2026-33022

A user with permission to create or update a TaskRun or PipelineRun can crash the Tekton Pipelines controller by setting .spec.taskRef.resolver (or .spec.pipelineRef.resolver) to a string of 31 characters or more, causing a denial of service for all reconciliation.

Details

The controller panics in GenerateDeterministicNameFromSpec when building a deterministic ResolutionRequest name. The generated name has the format {resolver}-{hash} and, when the resolver name is long enough, the result exceeds the DNS-1123 label limit of 63 characters.

The truncation logic attempts to find a word boundary using strings.LastIndex(name, " "). Since the generated name never contains spaces (it is composed of the resolver name, a dash, and a hex-encoded hash), LastIndex returns -1, which is then used as a slice bound:

return name[:strings.LastIndex(name[:maxLength], " ")], nil
// strings.LastIndex returns -1 → panic: slice bounds out of range [:-1]

The panic crashes the controller. Because the offending TaskRun or PipelineRun is re-reconciled on restart, the controller enters a CrashLoopBackOff, blocking all TaskRun and PipelineRun reconciliation cluster-wide until the offending resource is manually deleted.

Built-in resolvers use short names (git, cluster, bundles, hub) and are not affected under normal usage. The vulnerability is exploitable by any user who can create TaskRuns or PipelineRuns with a custom resolver name.

Workarounds

Restrict who can create TaskRun and PipelineRun resources via Kubernetes RBAC. There is no validation-side workaround without patching.

Affected Versions

All releases from v0.60.0 through v1.10.0.

The vulnerable truncation logic was introduced in commit ea1fa7ad1fdc ("Remote Resolution Refactor"), first released in v0.60.0 (2024-05-22).

Currently supported affected releases:

• v1.10.x (latest)
• v1.9.x (LTS, EOL 2027-01-30)
• v1.6.x (LTS, EOL 2026-10-31)
• v1.3.x (LTS, EOL 2026-08-04)
• v1.0.x (LTS, EOL 2026-04-29)

Releases prior to v0.60.0 are not affected, the truncation code did not exist.

Acknowledgments

This vulnerability was reported by Oleh Konko (@1seal), who provided a thorough vulnerability analysis, proof-of-concept, and review of the fix. Thank you!

References

• Fix (main): 5eead3f859b9
• Fix (v1.10.x): 01673237c464
• Fix (v1.9.x): edc64bbf2232
• Fix (v1.6.x): 0fa2d66cff81
• Fix (v1.3.x): 5e4905fb6754
• Fix (v1.0.x): ebc197e2b973
• Introduced in: ea1fa7ad1fdc ("Remote Resolution Refactor")

Denial of service, A single malicious TaskRun or PipelineRun with a long resolver name is sufficient to crash the Tekton Pipelines controller into a restart loop, blocking all CI/CD reconciliation cluster-wide until the resource is removed.

Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service. Typical impact: denial of service.

CVE-2026-33022 has a CVSS score of 6.5 (Medium). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (1.0.1, 1.3.3, 1.6.1, 1.9.2, 1.10.2); upgrading removes the vulnerable code path.

Kodem intelligence

Fixed in versions 1.0.1, 1.3.3, 1.6.1, 1.9.2, 1.10.2.

The fix computes the hash first, then truncates only the prefix (resolver name) to fit within the DNS-1123 label limit, preserving the full hash to maintain determinism and uniqueness of ResolutionRequest names.

1. What is CVE-2026-33022? CVE-2026-33022 is a medium-severity uncontrolled resource consumption vulnerability in github.com/tektoncd/pipeline (go), affecting versions >= 0.60.0, < 1.0.1. It is fixed in 1.0.1, 1.3.3, 1.6.1, 1.9.2, 1.10.2. Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service.
2. How severe is CVE-2026-33022? CVE-2026-33022 has a CVSS score of 6.5 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of github.com/tektoncd/pipeline are affected by CVE-2026-33022? github.com/tektoncd/pipeline (go) versions >= 0.60.0, < 1.0.1 is affected.
4. Is there a fix for CVE-2026-33022? Yes. CVE-2026-33022 is fixed in 1.0.1, 1.3.3, 1.6.1, 1.9.2, 1.10.2. Upgrade to this version or later.
5. Is CVE-2026-33022 exploitable, and should I be worried? Whether CVE-2026-33022 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-33022 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-33022?
   • Upgrade github.com/tektoncd/pipeline to 1.0.1 or later
   • Upgrade github.com/tektoncd/pipeline to 1.3.3 or later
   • Upgrade github.com/tektoncd/pipeline to 1.6.1 or later
   • Upgrade github.com/tektoncd/pipeline to 1.9.2 or later
   • Upgrade github.com/tektoncd/pipeline to 1.10.2 or later