CVE-2026-82281

CVE-2026-82281 is an authorization bypass flaw (CWE-639, user-controlled key without ownership check) in Kotaemon, an open-source retrieval-augmented generation (RAG) chat UI, affecting all releases through 0.12.0. The select_conv, delete_conv, rename_conv, and on_set_public_conversation functions in control.py accept user-supplied conversation identifiers without verifying that the conversation belongs to the requesting user. By supplying an arbitrary or guessed conversation identifier over the network (no authentication beyond normal access is required, though the high attack complexity means the attacker needs a valid or discoverable conversation ID), an attacker can read other users' chat histories and delete or rename conversations they do not own. Any Kotaemon deployment through 0.12.0 serving multiple users is affected, since cross-account access is what the missing checks enable. Exploitation is not currently known: there is no public proof-of-concept, the flaw is not in CISA's KEV, and EPSS estimates only about a 0.3% chance of exploitation within 30 days.

What to do: No fixed version is named in the available data, so monitor the Kotaemon project for a patched release and upgrade beyond 0.12.0 as soon as one is published. Until then, restrict Kotaemon instances to trusted users and internal networks (e.g., via VPN or reverse-proxy access controls), avoid sharing instances with untrusted users, and review server logs for unexpected conversation reads, deletions, or renames across accounts.