Arkon EUVD-2026-103008

Exploitation requires a valid authenticated employee account on an Arkon instance (through 0.9.2) and knowledge or enumeration of another department's source IDs; the attacker then calls the by-id source routes (plan, progress, PATCH, retry, approve-extraction) in app/routers/sources.py, which omit the can_access_document authorization check. Meaningful impact depends on a multi-department/multi-tenant deployment where cross-department data isolation is expected. Limiting factors: valid low-privileged credentials are mandatory (PR:L, so not remote-unauthenticated), no user interaction is needed, disclosure is confined to derived wiki titles/summaries and ingestion-state fields rather than raw source content, and there is no availability impact.

This is a moderate, authorization-layer (IDOR) flaw, not a top-tier priority. The CVSS 4.0 vector (AV:N/AC:L/AT:N/PR:L/UI:N) confirms network reach and low attack complexity but requires existing low-privileged authentication (PR:L), and impact is limited to low confidentiality and low integrity (VC:L/VI:L) with no availability impact (VA:N) and no scope/subsequent-system change - consistent with the 5.3 (Medium) base score. No EPSS score was supplied and the CVE is not listed in CISA KEV, so there is no signal of widespread or active exploitation. A detailed public technical writeup exists (hackmd) describing the cross-department IDOR, which lowers the effort to reproduce, but this is distinct from confirmed exploitation. The practical risk is bounded by two factors the raw score does not fully convey: the attacker must already be an authenticated employee, and the exposed data is limited to derived wiki titles/summaries and ingestion-state fields rather than full source content. Net assessment: a legitimate but not urgent issue - meaningful in multi-tenant/multi-department Arkon deployments where tenant isolation matters, low priority elsewhere.

A low-privileged but authenticated employee in one department enumerates or guesses source IDs belonging to another department and calls the vulnerable by-id routes (plan, progress, PATCH, retry, approve-extraction) in app/routers/sources.py, which never invoke can_access_document. They thereby read derived wiki titles and summaries from foreign sources and modify ingestion state. A public technical writeup detailing this IDOR is available, lowering the barrier to reproduction, though no packaged exploit code is confirmed; the attack is network-reachable with low complexity but needs valid credentials.