{"id":"CVE-2026-118761","aliases":["GHSA-8fmv-6rg5-5924"],"url":"https://o3.security/vulnerability/CVE-2026-118761","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.","published":"2026-10-29T16:37:44.333Z","modified":"2026-10-31T02:47:37.045832356Z","cvss":{"score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"Go","name":"github.com/kubeflow/pipelines","fixedVersion":"0.0.0-20260831164314-ba9ae72cc860"},{"ecosystem":"Go","name":"github.com/kubeflow/pipelines","fixedVersion":null}],"fix":{"url":"https://github.com/kubeflow/pipelines/commit/1121d9a081fdf9e2107c39abb2cd8947727c6953","label":"kubeflow/pipelines@1121d9a"},"references":[{"type":"WEB","url":"https://github.com/kubeflow/pipelines/releases/tag/2.18.0"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/118xxx/CVE-2026-118761.json"},{"type":"ADVISORY","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":"FIX","url":"https://github.com/kubeflow/pipelines/commit/1121d9a081fdf9e2107c39abb2cd8947727c6953"},{"type":"FIX","url":"https://github.com/kubeflow/pipelines/commit/ba9ae72cc860e3afbea232185e4132fc2896cac5"},{"type":"FIX","url":"https://github.com/kubeflow/pipelines/pull/14171"},{"type":"FIX","url":"https://github.com/kubeflow/pipelines/pull/14186"},{"type":"PACKAGE","url":"https://github.com/kubeflow/pipelines"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-10-31T02:47:37.045832356Z"}}