High severity · published Oct 2, 2025
CVE-2025-59835
LangBot has a cross-directory file upload vulnerability, which could lead to system takeover
8.6
CVSS
0.4%
EPSS
No
On KEV
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.
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 36% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
LA
LangBot · langbot-app
>= 4.1.0, < 4.3.5 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-59835
CVE.org
https://www.cve.org/CVERecord?id=CVE-2025-59835
github.com
https://github.com/langbot-app/LangBot/pull/1691
github.com
https://github.com/langbot-app/LangBot/releases/tag/v4.3.5
github.com
https://github.com/langbot-app/LangBot/security/advisories/GHSA-7j3j-qj83-9qv4
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