Tekton Pipelines: Controller can panic when setting long resolver names in TaskRun/PipelineRun

Tekton Pipelines project provides k8s-style resources for declaring CI/CD-style pipelines. Versions 0.60.0 through 1.0.0, 1.1.0 through 1.3.2, 1.4.0 through 1.6.0, 1.7.0 through 1.9.0, 1.10.0, and 1.10.1 have a denial-of-service vulnerability in that allows any user who can create a TaskRun or PipelineRun to crash the controller cluster-wide by setting .spec.taskRef.resolver (or .spec.pipelineRef.resolver) to a string of 31+ characters. The crash occurs because GenerateDeterministicNameFromSpec produces a name exceeding the 63-character DNS-1123 label limit, and its truncation logic panics on a [-1] slice bound since the generated name contains no spaces. Once crashed, the controller enters a CrashLoopBackOff on restart (as it re-reconciles the offending resource), blocking all CI/CD reconciliation until the resource is manually deleted. Built-in resolvers (git, cluster, bundles, hub) are unaffected due to their short names, but any custom resolver name triggers the bug. The fix truncates the resolver-name prefix instead of the full string, preserving the hash suffix for determinism and uniqueness. This issue has been patched in versions 1.0.1, 1.3.3, 1.6.1, 1.9.2 and 1.10.2.

Tekton Pipelines project provides k8s-style resources for declaring CI/CD-style pipelines. Versions 0.60.0 through 1.0.0, 1.1.0 through 1.3.2, 1.4.0 through 1.6.0, 1.7.0 through 1.9.0, 1.10.0, and 1.10.1 have a denial-of-service vulnerability in that allows any user who can create a TaskRun or PipelineRun to crash the controller cluster-wide by setting .spec.taskRef.resolver (or .spec.pipelineRef.resolver) to a string of 31+ characters. The crash occurs because GenerateDeterministicNameFromSpec produces a name exceeding the 63-character DNS-1123 label limit, and its truncation logic panics on a [-1] slice bound since the generated name contains no spaces. Once crashed, the controller enters a CrashLoopBackOff on restart (as it re-reconciles the offending resource), blocking all CI/CD reconciliation until the resource is manually deleted. Built-in resolvers (git, cluster, bundles, hub) are unaffected due to their short names, but any custom resolver name triggers the bug. The fix truncates the resolver-name prefix instead of the full string, preserving the hash suffix for determinism and uniqueness. This issue has been patched in versions 1.0.1, 1.3.3, 1.6.1, 1.9.2 and 1.10.2.

Tekton Pipelines project provides k8s-style resources for declaring CI/CD-style pipelines. Versions 0.60.0 through 1.0.0, 1.1.0 through 1.3.2, 1.4.0 through 1.6.0, 1.7.0 through 1.9.0, 1.10.0, and 1.10.1 have a denial-of-service vulnerability in that allows any user who can create a TaskRun or PipelineRun to crash the controller cluster-wide by setting .spec.taskRef.resolver (or .spec.pipelineRef.resolver) to a string of 31+ characters. The crash occurs because GenerateDeterministicNameFromSpec produces a name exceeding the 63-character DNS-1123 label limit, and its truncation logic panics on a [-1] slice bound since the generated name contains no spaces. Once crashed, the controller enters a CrashLoopBackOff on restart (as it re-reconciles the offending resource), blocking all CI/CD reconciliation until the resource is manually deleted. Built-in resolvers (git, cluster, bundles, hub) are unaffected due to their short names, but any custom resolver name triggers the bug. The fix truncates the resolver-name prefix instead of the full string, preserving the hash suffix for determinism and uniqueness. This issue has been patched in versions 1.0.1, 1.3.3, 1.6.1, 1.9.2 and 1.10.2.

### Summary 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: ```go 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. ### Impact **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. ### Patches 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. ### 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](https://github.com/tektoncd/pipeline/commit/5eead3f859b9f938e86039e4d29185092c1d4ee6) - Fix (v1.10.x): [01673237c464](https://github.com/tektoncd/pipeline/commit/01673237c464cfac7e286183f5c9e9d6ec951a64) - Fix (v1.9.x): [edc64bbf2232](https://github.com/tektoncd/pipeline/commit/edc64bbf22323fcf218170f19047c9bcd8163e90) - Fix (v1.6.x): [0fa2d66cff81](https://github.com/tektoncd/pipeline/commit/0fa2d66cff814838c3a10cce252104c7fe618932) - Fix (v1.3.x): [5e4905fb6754](https://github.com/tektoncd/pipeline/commit/5e4905fb6754efa5ecea54de195738d73fb0e01d) - Fix (v1.0.x): [ebc197e2b973](https://github.com/tektoncd/pipeline/commit/ebc197e2b9733deedaa1624212ec66dcdf61eaaf) - Introduced in: `ea1fa7ad1fdc` ("Remote Resolution Refactor")

Tekton Pipelines controller panic via long resolver name in TaskRun/PipelineRun in github.com/tektoncd/pipeline