CVE-2026-118761 is a high-severity (CVSS 7.5) CWE-409 vulnerability in github.com/kubeflow/pipelines. A fix is available for github.com/kubeflow/pipelines — see the affected versions and patch details below.
Kubeflow Pipelines: Pipeline archive upload allows decompression bomb to exhaust server memory
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-118761.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2026-118761 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 398,142 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
github.com/kubeflow/pipelines🐹github.com/kubeflow/pipelinesReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Summary
The 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.
Multipart 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.
The amount of expansion needed to exhaust memory depends on deployment resource limits and concurrent activity; no particular archive is guaranteed to crash every deployment.
Remediation
Upgrade the API server to Kubeflow Pipelines 2.18.0. Versions through 2.17.3 are affected; the first affected release has not been established.
PR #14171 bounds compressed input and extracted pipeline data. PR #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.
Until 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.
Credit
bugbunny.ai discovered and reported the issue. Ayush Gupta (@Ayush-kathil) authored the archive fixes in #14171 and #14186, with Jeff Spahr (@jeffspahr) contributing regression coverage to #14171.
@BrianWillows later submitted a mixed report that included source analysis of pipeline-archive decompression.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/kubeflow/pipelines | all versions | 0.0.0-20260831164314-ba9ae72cc860go get github.com/kubeflow/pipelines@v0.0.0-20260831164314-ba9ae72cc860 |
| 🐹Go | github.com/kubeflow/pipelines | all versions | No fix |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/kubeflow/pipelines, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/kubeflow/pipelines to 0.0.0-20260831164314-ba9ae72cc860 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-118761 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Frequently Asked Questions
Is CVE-2026-118761 in your dependencies?
Find it across Go, including transitive dependencies.