{"id":"GHSA-8fmv-6rg5-5924","summary":"Kubeflow Pipelines: Pipeline archive upload allows decompression bomb to exhaust server memory","details":"## Summary\n\nThe Kubeflow Pipelines API server decompresses uploaded pipeline archives without adequately bounding expanded data in affected versions. A small ZIP or gzip-compressed tar archive can consume disproportionately large amounts of memory while the server locates or reads the pipeline file, potentially exhausting API-server resources and interrupting service.\n\nMultipart pipeline and pipeline-version upload processing decompresses the archive before namespace authorization, so a caller who can reach those endpoints does not need a successful pipeline-create authorization decision to trigger the issue. External authentication and network controls can restrict reachability. URL-import handlers authorize before fetching and decompressing a remote archive.\n\nThe amount of expansion needed to exhaust memory depends on deployment resource limits and concurrent activity; no particular archive is guaranteed to crash every deployment.\n\n## Remediation\n\nUpgrade the API server to **[Kubeflow Pipelines 2.18.0](https://github.com/kubeflow/pipelines/releases/tag/2.18.0)**. Versions through 2.17.3 are affected; the first affected release has not been established.\n\n[PR #14171](https://github.com/kubeflow/pipelines/pull/14171) bounds compressed input and extracted pipeline data. [PR #14186](https://github.com/kubeflow/pipelines/pull/14186) strengthens the total tar traversal budget, including metadata and skipped entries. The 2.18 release also includes configurable upload and specification limits; operators should review the shipped settings and resource budget. These controls address pipeline archive amplification and do not establish general HTTP-body, temporary-disk, concurrency, or CPU limits.\n\nUntil upgrading, restrict access to upload and import endpoints and apply deployment-level request and resource controls. A compressed upload-size limit alone does not prevent decompression amplification. Regression tests cover compressed input, selected-entry boundaries, and tar traversal budgets; no deployed-server OOM test was performed for this assessment.\n\n## Credit\n\n[bugbunny.ai](https://bugbunny.ai) discovered and reported the issue. Ayush Gupta ([@Ayush-kathil](https://github.com/Ayush-kathil)) authored the archive fixes in #14171 and #14186, with Jeff Spahr ([@jeffspahr](https://github.com/jeffspahr)) contributing regression coverage to #14171.\n\n[@BrianWillows](https://github.com/BrianWillows) later submitted a mixed report that included source analysis of pipeline-archive decompression.","aliases":["CVE-2026-118761"],"modified":"2026-10-30T23:30:04.079827623Z","published":"2026-10-30T23:13:38Z","database_specific":{"github_reviewed_at":"2026-10-30T23:13:38Z","nvd_published_at":"2026-10-29T17:18:06Z","cwe_ids":["CWE-409"],"severity":"HIGH","github_reviewed":true},"references":[{"type":"WEB","url":"https://github.com/kubeflow/pipelines/security/advisories/GHSA-8fmv-6rg5-5924"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-118761"},{"type":"WEB","url":"https://github.com/kubeflow/pipelines/pull/14171"},{"type":"WEB","url":"https://github.com/kubeflow/pipelines/pull/14186"},{"type":"WEB","url":"https://github.com/kubeflow/pipelines/commit/1121d9a081fdf9e2107c39abb2cd8947727c6953"},{"type":"WEB","url":"https://github.com/kubeflow/pipelines/commit/ba9ae72cc860e3afbea232185e4132fc2896cac5"},{"type":"PACKAGE","url":"https://github.com/kubeflow/pipelines"},{"type":"WEB","url":"https://github.com/kubeflow/pipelines/releases/tag/2.18.0"}],"affected":[{"package":{"name":"github.com/kubeflow/pipelines","ecosystem":"Go","purl":"pkg:golang/github.com/kubeflow/pipelines"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"0.0.0-20260831164314-ba9ae72cc860"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/10/GHSA-8fmv-6rg5-5924/GHSA-8fmv-6rg5-5924.json"}},{"package":{"name":"github.com/kubeflow/pipelines","ecosystem":"Go","purl":"pkg:golang/github.com/kubeflow/pipelines"},"versions":["1.7.0-alpha.3"],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/10/GHSA-8fmv-6rg5-5924/GHSA-8fmv-6rg5-5924.json"}}],"schema_version":"1.9.2","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}