CVE-2025-56526

Kotaemon through 0.12.0 contains an insecure deserialization vulnerability in the check_connection endpoint that allows unauthenticated attackers to instantiate arbitrary Python classes by supplying crafted YAML/JSON input with a __type__ field. Attackers can exploit this to override the __type__ field with subprocess.check_output and arbitrary arguments, achieving remote code execution with application process privileges.

Cinnamon's Kotaemon (all versions up to and including v0.12.0) multi-user chat interface contains multiple vulnerabilities due to incorrect authorization and improper access controls. There are four handler methods in `libs/ktem/ktem/pages/chat/control.py` that load a Conversation record by its ID without comparing the requester's `user_id` to the conversation's owner `Conversation.user`. This allows any authenticated user to perform the following actions: 1. Read other user's chat transcripts, RAG retrieval history, AI-generated plots, and chat suggestions. 2. Permanently delete another user's conversation. 3. Rename another user's conversation. 4. Overwrite another user's conversation's chat suggestion list.

Kotaemon through 0.12.0 fails to properly validate conversation ownership in select_conv, delete_conv, rename_conv, and on_set_public_conversation functions in control.py. Attackers can read other users' chat histories, delete conversations, or rename conversations by supplying arbitrary conversation identifiers without proper authorization checks.

In Cinnamon kotaemon 0.11.0, the _may_extract_zip function in libs/ktem/ktem/index/file/ui.py does not check the contents of uploaded ZIP files. Although contents are extracted into a temporary folder, successfully uploading a ZIP bomb can still cause excessive resource consumption during decompression, and if no further files are uploaded, extracted data may occupy disk space and potentially render the system unavailable.

Plaintext password storage in Kotaemon 0.11.0 in the client's localStorage. The flaw allows access to passwords through XSS attacks or physical access to the browser.