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PatchSiren cyber security CVE debrief

CVE-2026-111620 O2OA CVE debrief

CVE-2026-111620 is an authorization bypass vulnerability in O2OA through 10.0.2-ce that allows authenticated users to download attachments from other works via the attachment download endpoint. The vulnerability exists because ActionDownloadWithWork and ActionDownloadWithWorkStream do not verify that the requested attachment ID belongs to the referenced work or draft. Attackers who know an attachment UUID can request it through the jaxrs/attachment/download/{id}/work/{workId} endpoint to read documents attached to other users' processes.

Vendor
O2OA
Product
Unknown
CVSS
MEDIUM 6
CISA KEV
Not listed in stored evidence
Original CVE published
2026-10-16
Original CVE updated
2026-10-19
Advisory published
2026-10-16
Advisory updated
2026-10-19

Who should care

System administrators, security teams, and users with access to the affected endpoint should assess exposure and prioritize remediation. This vulnerability requires attention from those responsible for securing O2OA installations, particularly in environments where sensitive information is stored or processed.

Why it matters

CVE-2026-111620 is a medium-severity vulnerability in O2OA that allows authenticated users to download attachments from other works via the attachment download endpoint. System administrators and security teams should assess exposure and prioritize remediation to prevent potential data breaches or unauthorized information disclosure.

  • Authenticated users may access sensitive information without proper authorization
  • Potential data breaches or unauthorized information disclosure
  • Need for additional monitoring and logging to detect potential abuse
  • Remediation priority based on medium CVSS score and potential impact

Technical summary

The vulnerability exists in the x_processplatform_assemble_surface component of O2OA through 10.0.2-ce. The ActionDownloadWithWork and ActionDownloadWithWorkStream endpoints do not properly validate the attachment ID, allowing authenticated users to download attachments from other works or drafts. This can lead to unauthorized access to sensitive information. System administrators and security teams should assess exposure and prioritize remediation to prevent potential data breaches or unauthorized information disclosure.

Defensive priority

Medium-priority defensive actions are required to address this vulnerability, as it allows authenticated users to access sensitive information. System administrators and security teams should assess exposure and prioritize remediation.

Recommended defensive actions

  • Assess exposure by identifying systems and users with access to the affected endpoint
  • Verify that attachment IDs are properly validated and restrict access to authorized users
  • Implement additional monitoring and logging to detect potential abuse
  • Prioritize remediation based on the medium CVSS score and potential impact
  • Review compensating controls for exposed systems while remediation is scheduled and verified
  • Check relevant monitoring, detection, and logs for exposed assets that need extra review
  • Track exceptions, retest remediated assets, and close the item only after evidence is documented.

Evidence notes

The CVE record and source item provide details about the vulnerability, including its description, affected versions, and references. However, the corpus does not establish versions beyond 10.0.2-ce, exploitation, impact, or remediation, which require verification from the supplied official sources.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-111620 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-111620

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-111620 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-111620

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

  • O2OA through 10.0.2-ce Cross-Work Attachment Read via Attachment Download Endpoint

    Unverified legacy reference

    URL: https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/111xxx/CVE-2026-111620.json

    cve_program_cvelist_v5

  • Source reference

    Unverified legacy reference

    URL: https://hackmd.io/@hieuPenguinnn/o2oa-processplatform-attachment-download-work-cross-work-idor

    Supplemental source - third-party-advisory

  • Source reference

    Unverified legacy reference

    URL: https://github.com/o2oa/o2oa/blob/10.0.2-ce/o2server/x_processplatform_assemble_surface/src/main/java/com/x/processplatform/assemble/surface/jaxrs/attachment/ActionDownloadWithWork.java

    Supplemental source - technical-description

  • Source reference

    Unverified legacy reference

    URL: https://github.com/o2oa/o2oa/blob/10.0.2-ce/o2server/x_processplatform_assemble_surface/src/main/java/com/x/processplatform/assemble/surface/jaxrs/attachment/ActionDownloadWithWorkStream.java

    Supplemental source - technical-description

  • Source reference

    Unverified legacy reference

    URL: https://github.com/o2oa/o2oa

    Supplemental source - product

  • Source reference

    Unverified legacy reference

    URL: https://www.vulncheck.com/advisories/o2oa-through-10.0.2-ce-cross-work-attachment-read-via-attachment-download-endpoint

    Supplemental source - third-party-advisory

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.