CVE intelligence and bounded remediation

CVE-2025-59835 — LangBot is a global IM bot platform designed for LLMs

High CVSS 8.6

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.

Severity
High
CVSS
8.6 (4.0)
Published
2025-10-02
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-23, CWE-434

Affected products

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Matched remediation archetype

Path traversal, unsafe upload, and file handling

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Trace untrusted filenames, archive entries, URLs, and path segments into read, write, include, extraction, and upload operations.
  • Identify filesystem roots, mount permissions, symbolic-link behavior, archive handling, and whether uploaded content is web-accessible or executable.
  • Review canonicalization and containment checks across supported operating systems and storage backends.

Remediate safely

  • Generate server-side storage identifiers and resolve paths beneath a fixed root using filesystem-aware containment checks.
  • Reject absolute, parent-relative, alternate-separator, device, link, and archive entries that escape the intended root.
  • Store uploads outside executable or served paths, validate type and size, and use private atomic temporary files.

Authoritative sources

Complete CVE record and remediation plan

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