Vulnerability · Published Oct 2, 2025 · Assigned by GitHub_M

CVE-2025-59835LangBot has a cross-directory file upload vulnerability, which could lead to system takeover

High 8.6

In plain English

A high-severity unrestricted file upload in LangBot from langbot-app. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 36% of all known vulnerabilities).

Severity (CVSS 4.0)8.6High

Exploit odds (30 days)0.4%top 63.6% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

LangBot is a global IM bot platform designed for LLMs. In versions 4.1.0 up to but not including 4.3.5, authorized attackers can exploit the /api/v1/files/documents interface to perform arbitrary file uploads. Since this interface does not strictly restrict the storage directory of files on the server, it is possible to upload dangerous files to specific system directories. This is fixed in version 4.3.5.

Affected products (as reported)

Vendor	Product	Versions
langbot-app	LangBot	>= 4.1.0, < 4.3.5

Weakness: CWE-23, CWE-434 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:P

References

https://github.com/langbot-app/LangBot/security/advisories/GHSA-7j3j-qj83-9qv4 x_refsource_CONFIRM
https://github.com/langbot-app/LangBot/pull/1691 x_refsource_MISC
https://github.com/langbot-app/LangBot/releases/tag/v4.3.5 x_refsource_MISC