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PatchSiren cyber security CVE debrief

CVE-2026-111704 LangChat CVE debrief

LangChat through commit 2a6285a contains a missing authentication vulnerability that allows unauthenticated remote attackers to access REST controllers because no Sa-Token interceptor is registered. Attackers can query /api/v1/auth/users to read plaintext passwords, retrieve LLM provider API keys, create super-admin accounts, and modify or delete data.

Vendor
LangChat
Product
Unknown
CVSS
CRITICAL 9.3
CISA KEV
Not listed in stored evidence
Original CVE published
2026-10-16
Original CVE updated
2026-10-21
Advisory published
2026-10-16
Advisory updated
2026-10-21

Who should care

Defenders responsible for LangChat deployments, especially those using versions up to commit 2a6285a, should assess exposure and prioritize verifying the presence of authentication mechanisms and implementing compensating controls.

Why it matters

The missing authentication vulnerability in LangChat through commit 2a6285a allows unauthenticated remote attackers to access REST controllers and perform sensitive actions, posing a critical risk to LangChat deployments.

  • Verify authentication mechanisms in LangChat deployments
  • Implement compensating controls to restrict access to sensitive REST API endpoints
  • Monitor for suspicious activity on LangChat systems

Technical summary

The vulnerability is caused by the lack of a Sa-Token interceptor in LangChat through commit 2a6285a, allowing unauthenticated remote attackers to access REST controllers and perform sensitive actions. This critical risk enables attackers to query /api/v1/auth/users to read plaintext passwords, retrieve LLM provider API keys, create super-admin accounts, and modify or delete data. Defenders should prioritize verifying the presence of authentication mechanisms in LangChat deployments, especially those using versions up to commit 2a6285a, and consider implementing compensating controls to restrict access to sensitive REST API endpoints.

Defensive priority

Defenders should prioritize verifying the presence of authentication mechanisms in LangChat deployments, especially those using versions up to commit 2a6285a, and consider implementing compensating controls to restrict access to sensitive REST API endpoints.

Recommended defensive actions

  • Verify the presence of authentication mechanisms in LangChat deployments
  • Implement compensating controls to restrict access to sensitive REST API endpoints
  • Monitor for suspicious activity on LangChat systems
  • Review compensating controls for exposed systems while remediation is scheduled and verified
  • Check relevant monitoring, detection, and logs for exposed assets that need extra review
  • Track exceptions, retest remediated assets, and close the item only after evidence is documented
  • Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and source item provide details on the missing authentication vulnerability in LangChat through commit 2a6285a. The vulnerability allows unauthenticated remote attackers to access REST controllers and perform sensitive actions.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-111704 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-111704

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-111704 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-111704

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

  • LangChat through commit 2a6285a Missing Authentication on REST API Controllers

    Unverified legacy reference

    URL: https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/111xxx/CVE-2026-111704.json

    cve_program_cvelist_v5

  • Source reference

    Unverified legacy reference

    URL: https://hackmd.io/@hieuPenguinnn/langchat-missing-global-auth-credential-exposure

    Supplemental source - third-party-advisory

  • Source reference

    Unverified legacy reference

    URL: https://github.com/LangChat/langchat/blob/2a6285a6b8c51d51cdc599771bb667a30bc03f5c/langchat-server/src/main/java/cn/langchat/server/config/WebAsyncConfig.java

    Supplemental source - technical-description

  • Source reference

    Unverified legacy reference

    URL: https://github.com/LangChat/langchat/blob/2a6285a6b8c51d51cdc599771bb667a30bc03f5c/langchat-auth/src/main/java/cn/langchat/auth/controller/AigcUserController.java

    Supplemental source - technical-description

  • Source reference

    Unverified legacy reference

    URL: https://github.com/LangChat/langchat/blob/2a6285a6b8c51d51cdc599771bb667a30bc03f5c/langchat-auth/src/main/java/cn/langchat/auth/service/impl/AuthServiceImpl.java

    Supplemental source - technical-description

  • Source reference

    Unverified legacy reference

    URL: https://www.vulncheck.com/advisories/langchat-through-commit-2a6285a-missing-authentication-on-rest-api-controllers

    Supplemental source - third-party-advisory

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.