Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain
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AccessAuthenticate as low-privileged O2OA user
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DeliveryObtain valid attachment UUID
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ExploitRequest download/{id}/work/{workId} with visitable work
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ExecutionServer skips ownership validation
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ImpactRead other users' process attachments
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A01:2025 - Broken Access Control
ASVS 5.0
V8 - Authorization Object-level authorization, IDOR prevention
|
| Exploitation Conditions | Requires an authenticated session as any low-privileged O2OA user (PR:L) plus knowledge of a specific target attachment's UUID, which is not sequentially enumerable (this is the AT:P attack requirement and the primary factor limiting mass exploitation). The attacker must also supply a work or draft they can legitimately visit or own as the {workId} parameter. The flaw is present because ActionDownloadWithWork and ActionDownloadWithWorkStream in x_processplatform_assemble_surface never confirm the requested attachment id belongs to the referenced work/draft. Affects O2OA through 10.0.2-ce. Limiting factors: valid credentials needed, UUID must be known or leaked, impact is read-only confidentiality (no integrity/availability effect, no code execution), and reach is bounded by O2OA's small deployment base. |
| Impact | This is a moderate-severity authenticated IDOR (CWE-639), not a drop-everything priority. The CVSS 4.0 vector (AV:N/AC:H/AT:P/PR:L/UI:N) is internally consistent with the description: network-reachable but requiring a valid low-privileged account (PR:L) and knowledge of a non-enumerable attachment UUID (reflected as AC:H plus AT:P - a genuine attack requirement, since UUIDs cannot be brute-forced at scale). Impact is confidentiality-only (VC:H, VI:N, VA:N), matching a read-only attachment-disclosure flaw. No CISA KEV listing and no explicit POC flag were provided, so exploitation is not confirmed in the wild; however, a detailed public technical writeup (HackMD) and a VulnCheck advisory exist, lowering the barrier to weaponization. There are no conflicting signals in the data - CVSS, description, and CWE all align on authenticated, confidentiality-impacting authorization bypass. The main uncertainty is real-world reach: O2OA is a niche platform, so this is a credible insider/lateral-movement data-leak risk rather than a mass-exploitation event. EPSS was not provided and cannot be commented on. |
| Exploit ScenarioDerived | A low-privileged but authenticated O2OA user who has obtained a valid attachment UUID (e.g., leaked in logs, shared links, or prior access) sends a request to jaxrs/attachment/download/{id}/work/{workId} supplying a work they can legitimately visit. Because ActionDownloadWithWork/ActionDownloadWithWorkStream never verify that the attachment belongs to the referenced work, the server returns another user's process document. No public exploit code is flagged, but a step-by-step technical writeup is publicly available. |
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Alert meAnalysisAIv1 – Oct 16, 2026
Authenticated cross-work attachment disclosure in O2OA through 10.0.2-ce lets any low-privileged user, using the endpoint jaxrs/attachment/download/{id}/work/{workId}, read files attached to other users' process works by supplying an attachment UUID they should not be able to reach. The root cause is an IDOR (CWE-639) in x_processplatform_assemble_surface, where the download actions never confirm the requested attachment belongs to the referenced work or draft, so the confidentiality of stored documents is exposed (vector reports C:H with no integrity or availability impact). Exploitation requires a valid low-privileged session plus knowledge of a specific, non-sequentially-enumerable attachment UUID, which keeps mass exploitation impractical; no public exploit code was identified at time of analysis and there is no CISA KEV entry confirming active exploitation.
RemediationAI
No vendor-released patch or fixed version was identified in the available intelligence for CVE-2026-111620; O2OA 10.0.2-ce is the newest build referenced, so treat remediation as compensating controls until an upstream fix appears. The most effective fix is code-level and low-risk: in ActionDownloadWithWork and ActionDownloadWithWorkStream, after loading the attachment, add an ownership assertion that the attachment's parent work/job identifier equals the {workId} path parameter and that the caller is entitled to view that work, rejecting the request otherwise - this mirrors the resource-scoping logic the platform already applies to work-item access and carries no functional downside beyond properly failing unauthorized downloads. Where source modification is not possible, front the jaxrs/attachment/download/... routes with a reverse proxy or WAF rule that restricts them to trusted networks or specific roles (trade-off: legitimate mobile and integration clients that rely on those URLs will break unless allowlisted), reduce the exposure window of attachment UUIDs by stripping raw attachment identifiers from client-side pages and outbound links, shortening URL lifetimes, and avoiding third-party referrer leakage, since the identifier's secrecy is the main thing preventing abuse. Enable and review audit logging on the download endpoints to spot enumeration or anomalous cross-user access, and monitor https://github.com/o2oa/o2oa and https://www.vulncheck.com/advisories/o2oa-through-10.0.2-ce-cross-work-attachment-read-via-attachment-download-endpoint for the release of an official fix and upgrade immediately once it is published.
Affected VersionsENISA
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 1 package in euvd
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Technical ContextAI · show details
O2OA is an open-source Java enterprise OA/low-code platform whose process engine is split into a domain layer and an HTTP surface layer, the latter exposed as JAX-RS style endpoints under a jaxrs/ path prefix. The vulnerable code lives in module x_processplatform_assemble_surface, in com.x.processplatform.assemble.surface.jaxrs.attachment.ActionDownloadWithWork and ActionDownloadWithWorkStream, which handle downloading an attachment in the context of a work item. Both actions resolve the attachment by the {id} path segment and stream its content, but never assert that the attachment's owning work or job matches the {workId} segment supplied in the URL - the user-controlled key problem that defines CWE-639 (authorization bypass through user-controlled key, commonly called IDOR). Because attachment identifiers are UUIDs rather than small sequential integers, the attacker must first obtain the identifier through leakage (shared links, referrer headers, exports, logs, or chat), and must also provide a work or draft that their session can legitimately open; these two prerequisites align with the assessed attack requirements (AT:P) and explain the AC:H rating alongside PR:L. The CPE cpe:2.3:a:o2oa:o2oa:*:*:*:*:*:*:*:* indicates every O2OA release up to and including 10.0.2-ce is in scope, and the public source references point directly at the 10.0.2-ce tag of the two affected action classes.
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Severity by source
CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
Network-reachable but needs a low-privileged account (PR:L) and knowledge of a non-guessable attachment UUID (AC:H); confidentiality-only disclosure, so C:H with I:N/A:N.
Primary rating from Vendor (VulnCheck).
CVSS VectorVendor: VulnCheck
DescriptionCVE.org
O2OA through 10.0.2-ce contains an authorization bypass vulnerability in x_processplatform_assemble_surface that allows authenticated users to download attachments from other works. ActionDownloadWithWork and ActionDownloadWithWorkStream never verify that the requested attachment id belongs to the referenced work or draft, so any visitable work or owned draft can be supplied. Attackers who know an attachment UUID can request it through jaxrs/attachment/download/{id}/work/{workId} to read documents attached to other users' processes.
Threat Intelligence Overview
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Authentication bypass attacks exploit flaws in the verification mechanisms that control access to systems and applications.
O2OA v6.4.7 was discovered to contain a remote code execution (RCE) vulnerability via /x_program_center/jaxrs/invoke. Ra
Remote Code Execution (RCE) vulnerability in o2oa version 8.1.2 and before, allows attackers to create a new interface i
An arbitrary file upload vulnerability in O2OA v8.3.8 allows attackers to execute arbitrary code via uploading a crafted
A weakness has been identified in O2OA up to 10.0-410. Rated medium severity (CVSS 5.1), this vulnerability is remotely
Improper authorization in o2oa up to version 10.0 allows remote attackers to bypass authentication via the syncFile func
O2OA versions up to 9.0.0 contain an XML external entity (XXE) injection vulnerability in the /x_program_center/jaxrs/mp
Information disclosure in O2OA (up to and including 9.5.3 and 10.0.2) lets an authenticated remote attacker read data th
Server-side request forgery (SSRF) in o2oa up to version 10.0 allows authenticated remote attackers to manipulate the fi
A vulnerability has been found in O2OA up to 10.0-410. Rated medium severity (CVSS 5.1), this vulnerability is remotely
A vulnerability was detected in O2OA up to 10.0-410. Rated medium severity (CVSS 5.1), this vulnerability is remotely ex
A vulnerability was determined in O2OA up to 10.0-410. Rated medium severity (CVSS 5.1), this vulnerability is remotely
A vulnerability has been found in O2OA up to 10.0-410. Rated medium severity (CVSS 5.1), this vulnerability is remotely
EUVD-2026-103042
GHSA-3hg3-468c-h77g
NVD
CVE.org
EPSS
VulDB
Exploit-DB