CVE-2026-121938 json
langchain4j-aideepin before 3.31.0 IDOR via GET /character/{uuid}
published 5d ago modified 5d ago also EUVD-2026-116895
- cvss
- 5.3
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.4%
- EPSS 0.4% chance of exploitation in 30 days, percentile 33%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- moyangzhan langchain4j-aideepin 3.31.0
Is CVE-2026-121938 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerCISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- no
- Technical impact
- partial
- Assessed
- 5d ago
Exploit prediction
0.39% chance of exploitation in the next 30 days, higher than 33% of all scored CVEs (FIRST EPSS, 2026-11-09).
Exploits and checks
- hackmd.io https://hackmd.io/@hieuPenguinnn/cve-2026-121938-langchain4j-aideepin-character-conversation-cross-user-idor referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 6.0 | 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 |
| CNA | 3.1 | 5.3 | CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N |
| CNA | 4.0 | 6.0 | 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
Affected products
- moyangzhan langchain4j-aideepin
Classification
- Weakness
-
- CWE-639 Authorization Bypass Through User-Controlled Key
References
-
github.com
/moyangzhan/langchain4j-aideepin/pull/117
issue-tracking, patch
-
github.com
/moyangzhan/langchain4j-aideepin/commit/9b2fee6b66836a0efd5599cfcddd05b80b05ca93
patch
-
hackmd.io
/@hieuPenguinnn/cve-2026-121938-langchain4j-aideepin-character-conversation-cross-user-idor
exploit
-
github.com
/moyangzhan/langchain4j-aideepin/issues/116
issue-tracking
-
hackmd.io
/@hieuPenguinnn/langchain4j-aideepin-character-conversation-cross-user-idor
third-party-advisory
-
github.com
/moyangzhan/langchain4j-aideepin/blob/v3.30.0/server/adi-common/src/main/java/com/moyz/adi/common/service/Char
technical-description
-
vulncheck.com
/advisories/langchain4j-aideepin-before-3.31.0-idor-via-get-character-uuid
third-party-advisory
Sources
- CVE List CVE-2026-121938
- NVD CVE-2026-121938
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.