HighCVE-2026-118761

    Kubeflow Pipelines: Pipeline archive upload allows decompression bomb to exhaust server memory (CVE-2026-118761)

    Published Last modified Sources: pwn.watch, OSV, Hersteller, CVE.org

    What is affected, what to do

    Update Kubeflow Pipeline View to version 2.18.0.

    Affected
    • Kubeflow Pipeline View lt *..2.18.0
    Fixed in
    • Kubeflow Pipeline View 2.18.0

    Not sure whether and how you are affected? Ask a question about this vulnerability

    Metrics

    7.5

    Priority

    XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.

    Source: Vendor (CNA), CVSS v3

    7.5

    CVSS v3

    Severity High on the scale from 0 to 10.

    Source: pwn.watch, OSV, Hersteller, CVE.org

    0.5 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 42.5

    Show all metrics
    Severity
    High
    Priority (0–325)

    The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?

    Read in glossary
    81.95 Methodology
    Exploit maturity

    An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.

    Read in glossary
    no public PoC known
    XIEM Effective CVSS

    XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command.

    Read in glossary
    7.5 Methodology
    CVSS v3

    CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.

    Read in glossary
    7.5
    EPSS score

    The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“.

    Read in glossary
    0.5 %
    Low — model estimates < 1% exploitation likelihood.
    EPSS percentile

    The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking.

    Read in glossary
    42.5
    High — this CVE ranks above the median of all CVEs scored today (rank ≥ 36%).
    KEV status

    The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.

    Read in glossary
    —
    Published
    CISA assessment (SSVC)
    Exploitation: none known · automatable · Technical impact: partial
    Source: CISA Vulnrichment, as of 29 October 2026
    CWE

    CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect.

    Read in glossary
    CWE-409

    Detection rules

    No NEOSEC detection rule is available for this vulnerability yet.

    Classification under NIS2 and CRA

    Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.

    NIS2

    NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.

    Read in glossary
    High technical severity: assess and remediate the vulnerability in vulnerability handling under Art. 21(2)(e) NIS2 and document the decision.
    CRA

    The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.

    Read in glossary
    From 11.12.2027, Annex I Part II CRA requires manufacturers of affected products with digital elements to handle vulnerabilities without delay and provide security updates.
    ISO/IEC 27001

    ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.

    Read in glossary
    Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.

    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.

    Source: pwn.watch, OSV (Open Source Vulnerabilities), GitHub Security Advisories, NVD (NIST), cvelistv5

    Affected products

    The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.

    Affected products
    Affected versionsFixed in
    kubeflowpipelines
    • < 2.18.0
    • 2.18.0
    gogithub.com/kubeflow/pipelines
    • —
    • = 1.7.0-alpha.3
    • 1.7.0-alpha.3
    • < 0.0.0-20260831164314-ba9ae72cc860
    • 0.0.0-20260831164314-ba9ae72cc860
    • —
    • —
    • 0.0.0-20260831164314-ba9ae72cc860

    Vendors and products

    Weakness classes (CWE)

    • CWE-409Improper Handling of Highly Compressed Data (Data Amplification)

      Base

      The product does not handle or incorrectly handles a compressed input with a very high compression ratio that produces a large output.

      Entry at MITRE CWE-409

    References & sources

    • github.comkubeflow/pipelines/commit/1121d9a081fdf9e2107c39abb2cd8947727c6…x_refsource_MISC, web
    • github.comkubeflow/pipelines/commit/ba9ae72cc860e3afbea232185e4132fc2896c…x_refsource_MISC, web
    • github.comkubeflow/pipelines/pull/14171x_refsource_MISC, web
    • github.comkubeflow/pipelines/pull/14186x_refsource_MISC, web
    • github.comkubeflow/pipelines/releases/tag/2.18.0x_refsource_MISC, pwn-watch, web
    • github.comkubeflow/pipelines/security/advisories/GHSA-8fmv-6rg5-5924x_refsource_CONFIRM, pwn-watch, web
    • pwn.watchpwn.watch: Kubeflow Pipelines: unauthenticated path traversal reads arbitrary files via volume artifacts (CVE-2026-118758), fixed in 2.18.0pwn-watch
    • github.comGHSA-2fg9-fx2f-439r: Volume artifact path traversal permits disclosure of process-readable filespwn-watch
    • CVE.org (MITRE)CVE-2026-118758: Kubeflow unauthenticated path traversal to arbitrary file read on ml-pipeline-uipwn-watch
    • github.comGHSA-wg5q-x4j9-qm54 (CVE-2026-118759): Run log streaming endpoint bypasses namespace authorizationpwn-watch
    • github.comGHSA-vjhf-6c8f-qhwj (CVE-2026-118760): Missing namespace authorization permits cross-tenant artifact readspwn-watch
    • NVD (NIST)vuln/detail/CVE-2026-118761advisory
    • github.comkubeflow/pipelinespackage

    Changes to this CVE

    Who changed this CVE and when: NVD (analysis, affected products, CVSS), the CVE publisher (CNA) and additional providers such as CISA (ADP).

    1. Record modifiedCISA ADP

      CISA assessment (SSVC): exploitation: none known, automatable: yes

      Show the original change
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      SSVC assessmentadded
      —
      {"id":"CVE-2026-118761","role":"CISA Coordinator","options":[{"exploitation":"none"},{"automatable":"yes"},{"technicalImpact":"partial"}],"version":"2.0.3","timestamp":"2026-10-29T20:18:49.737846Z"}

      Source identifier: 134c704f-9b21-4f2e-91b3-4a467353bcc0

    2. ReceivedGitHub

      CVSS V3.1: AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

      Weakness type: CWE-409

      Description added or changed

      Show 10 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Descriptionadded
      —
      Kubeflow Pipelines enables users to build and deploy portable, scalable machine learning workflows. Prior to 2.18.0, the API server decompressed uploaded pipeline archives without adequately bounding expanded data while locating or reading the pipeline file. A small ZIP or gzip-compressed tar archive can consume disproportionately large memory and exhaust API-server resources. Multipart pipeline and pipeline-version upload processing performs decompression before namespace authorization, so a reachable caller does not need a successful pipeline-create authorization decision. URL-import handlers authorize before fetching and decompressing a remote archive. The amount of expansion required to interrupt service depends on deployment resource limits and concurrent activity, and no specific archive is guaranteed to crash every deployment. This issue is fixed in version 2.18.0.
      CVSSadded
      —
      AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
      Weakness type (CWE)added
      —
      CWE-409
      Affected versions (publisher)added
      —
      New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/118xxx/CVE-2026-118761.json">CVE-2026-118761</a>
      Referenceadded
      —
      https://github.com/kubeflow/pipelines/commit/1121d9a081fdf9e2107c39abb2cd8947727c6953
      Referenceadded
      —
      https://github.com/kubeflow/pipelines/commit/ba9ae72cc860e3afbea232185e4132fc2896cac5
      Referenceadded
      —
      https://github.com/kubeflow/pipelines/pull/14171
      Referenceadded
      —
      https://github.com/kubeflow/pipelines/pull/14186
      Referenceadded
      —
      https://github.com/kubeflow/pipelines/releases/tag/2.18.0
      Referenceadded
      —
      https://github.com/kubeflow/pipelines/security/advisories/GHSA-8fmv-6rg5-5924

      Source identifier: security-advisories@github.com

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