| Component | LangChain |
| Severity | low (CVSS 2.6) |
| CVSS vector | CVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:N |
| Published (NVD) | 2026-05-05 |
| Last modified | 2026-07-24 |
| Affected versions | <= 0.3.1.3 read from the advisory text: NVD has not published CPE data yet |
| Fixed in | see the vendor advisory |
| Weakness | CWE-327CWE-328 |
| CISA KEV | not listed |
NVD description
A flaw has been found in chatchat-space Langchain-Chatchat up to 0.3.1.3. This issue affects the function PIL.Image.tobytes of the file libs/chatchat-server/chatchat/webui_pages/dialogue/dialogue.py of the component Vision Chat Paste Image Handler. This manipulation of the argument paste_image.image_data causes use of weak hash. The attacker needs to be present on the local network. The attack is considered to have high complexity. The exploitability is assessed as difficult. The exploit has been published and may be used. The project was informed of the problem early through an issue report but has not responded yet.
What to do
- NVD lists no fixed version yet: follow the vendor advisory below and keep LangChain off the public internet until a fix ships.
- Do not expose the component's API or UI to the internet without authentication in front of it.
Sources
- NVD: CVE-2026-7845
- https://github.com/3em0/cve_repo/blob/main/Langchain-Chatchat/Vuln-1-tobytes-Hash-Collision.md
- https://github.com/chatchat-space/Langchain-Chatchat/
- https://github.com/chatchat-space/Langchain-Chatchat/issues/5462
- https://vuldb.com/submit/807794
- https://vuldb.com/vuln/361124
- https://vuldb.com/vuln/361124/cti
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