CVE-2026-7846 Details
Description
A vulnerability has been found in chatchat-space Langchain-Chatchat up to 0.3.1.3. Impacted is the function files of the file libs/chatchat-server/chatchat/server/api_server/openai_routes.py of the component OpenAI-Compatible File Upload API. Such manipulation of the argument file.filename leads to time-of-check time-of-use. Access to the local network is required for this attack to succeed. The attack requires a high level of complexity. The exploitability is considered difficult. The exploit has been disclosed to the public and may be used. The project was informed of the problem early through an issue report but has not responded yet.
A time-of-check time-of-use (TOCTOU) vulnerability has been identified in Langchain-Chatchat versions through 0.3.1.3. The issue arises in the OpenAI-Compatible File Upload API, specifically within the file 'libs/chatchat-server/chatchat/server/api_server/openai_routes.py'. The vulnerability allows for a silent file overwrite by manipulating the 'file.filename' argument. This issue requires access to the local network for exploitation and is considered to have a high complexity.
The vulnerability can be addressed by modifying the file upload handling to include conflict detection and content integrity checks. One suggested approach is to introduce a random UUID to the filename to prevent collisions.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed May 5, 2026CISA-ADP
Assessed May 5, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/3em0/cve_repo/blob/main/Langchain-Chatchat/Vuln-2-Silent-File-Overwrite.md | [email protected] | ExploitTechnical Analysis |
| https://github.com/chatchat-space/Langchain-Chatchat/ | [email protected] | ProductVendor |
| https://github.com/chatchat-space/Langchain-Chatchat/issues/5463 | [email protected] | ExploitIssue TrackingTechnical DescriptionVendor |
| https://vuldb.com/submit/807795 | [email protected] | Permission Required |
| https://vuldb.com/vuln/361125 | [email protected] | AdvisoryPermission Required |
| https://vuldb.com/vuln/361125/cti | [email protected] | AdvisoryPermission Required |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-362 | Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') | [email protected] |
| CWE-367 | Time-of-check Time-of-use (TOCTOU) Race Condition | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| chatchat-space Langchain-Chatchat | All versions |
CPE
Remediation
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Change History
4 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 24, 2026 | CVE Translated | [email protected] |
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| May 5, 2026 | New CVE Received | [email protected] |