CVE-2026-121938
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.
Executive briefing
The source record describes: 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. The practical risk depends on whether an affected product/version is present, reachable and configured in an exploitable way. Review the affected-product evidence and linked vendor advisories before assigning exposure status.
Evidence confidence: Limited Evidence-derived, not an exploitability verdict
Severity & attack characteristics
CVSS vector: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
Technical explanation & impact
The technical mechanism is not expanded beyond the source description unless a referenced advisory supplies additional evidence. Read the linked vendor/CERT advisories for root-cause detail.
Potential impact must be interpreted from the published CVSS impact metrics and the affected component. A CVSS impact score is not proof that a particular asset is exploitable.
Weakness classification
CWE-639Affected products and versions
NVD has not supplied machine-readable vulnerable CPE product/version entries for this CVE. This is an information gap, not proof that no products are affected. Check the vendor advisory references below.
Remediation & validation
- Identify exposure by comparing the affected product and version ranges with your asset inventory, SBOM and externally exposed services.
- Review the linked vendor security advisory or patch notes. Upgrade to a vendor-confirmed fixed release; do not infer a fixed version from the CVE description.
- Until patched, consider restricting network access or disabling the affected feature where operationally safe. These are temporary controls, not a substitute for a vendor fix.
- Validate the remediation with a version check and vulnerability rescan, then retain change evidence.
No fixed version is displayed unless it is explicitly established by a vendor advisory. Follow the vendor's release notes for exact product and branch applicability.
Vendor advisories, patches & exploit references
- https://github.com/moyangzhan/langchain4j-aideepin/blob/v3.30.0/server/adi-common/src/main/java/com/moyz/adi/common/service/CharacterService.java#L105-L125 VENDOR disclosure@vulncheck.com
- https://github.com/moyangzhan/langchain4j-aideepin/commit/9b2fee6b66836a0efd5599cfcddd05b80b05ca93 VENDOR disclosure@vulncheck.com
- https://github.com/moyangzhan/langchain4j-aideepin/issues/116 VENDOR disclosure@vulncheck.com
- https://github.com/moyangzhan/langchain4j-aideepin/pull/117 VENDOR disclosure@vulncheck.com
- https://hackmd.io/@hieuPenguinnn/langchain4j-aideepin-character-conversation-cross-user-idor REFERENCE disclosure@vulncheck.com
- https://www.vulncheck.com/advisories/langchain4j-aideepin-before-3.31.0-idor-via-get-character-uuid REFERENCE disclosure@vulncheck.com
- https://hackmd.io/@hieuPenguinnn/cve-2026-121938-langchain4j-aideepin-character-conversation-cross-user-idor REFERENCE 134c704f-9b21-4f2e-91b3-4a467353bcc0
Information gaps & confidence notes
These gaps indicate missing source data. CVE Watch does not fill them with guessed product, exploit or patch details.
- NVD does not currently provide machine-readable vulnerable CPE product/version entries for this record.
Last enrichment: 2026-11-05T08:21:17+00:00 · Source last modified: 2026-11-04T19:17:34.013