CVE-2026-121938: langchain4j-aideepin before 3.31.0 IDOR via GET /character/{uuid}
langchain4j-aideepin before 3.31.0 contains an insecure direct object reference vulnerability that allows authenticated users to read other users' character-chat conversations by supplying their character uuid. Attackers can request GET /character/{uuid}, which CharacterService.detail resolves without an ownership check, to obtain victims' questions, AI answers, and attachment and audio URLs.
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
langchain4j-aideepinto a version that resolves this vulnerability.Fixed in 3.31.0
Event History
Frequently Asked Questions
Who can exploit this issue?
Any authenticated user can exploit it if they know or can supply another user's character UUID. The attack is performed through the GET /character/{uuid} endpoint and does not require user interaction.
What information could be exposed?
The vulnerable endpoint can disclose another user's character-chat conversations, including questions, AI-generated answers, attachment URLs, and audio URLs.
Which deployments are affected?
Versions before 3.31.0 are affected. Deployments exposing the character detail endpoint to authenticated users are at risk because the endpoint resolves character details without an ownership check.
How can I determine whether exploitation may have occurred?
Review authenticated requests to GET /character/{uuid} for users accessing UUIDs belonging to other accounts. Compare the requester identity with the owner of the requested character and investigate mismatches.