CVE-2025-59835Public exploitNetwork attack vector

Authenticated arbitrary file write via absolute pathname

Published Oct 2, 2025 · Updated Oct 2, 2025

Path traversal in LangBot 4.1.0 through 4.3.4 allows remote authenticated users to write uploaded files outside the storage directory. The /api/v1/files/documents handler passes a parsed, attacker-controlled absolute filename to os.path.join, causing Python to discard the data/storage base path. A valid login is required; successful writes can place startup content on Windows, while executable Linux placement depends on a suitable autostart directory.

CVSS severityUnavailable
Unscored
EPSS probability0.41%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Path traversal in LangBot 4.1.0 through 4.3.4 allows remote authenticated users to write uploaded files outside the storage directory. The /api/v1/files/documents handler passes a parsed, attacker-controlled absolute filename to os.path.join, causing Python to discard the data/storage base path. A valid login is required; successful writes can place startup content on Windows, while executable Linux placement depends on a suitable autostart directory.

The record

CVE
CVE-2025-59835
Published
Oct 2, 2025
Updated
Oct 2, 2025
Vendor
LangBot
Product
LangBot
Classifications
CWE-23, CWE-434, T1105
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 2, 2025CVE publishedPublication date reported by the CVE source.
  2. Oct 2, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= 4.1.0, < 4.3.5

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

LangBot · LangBotversion=>= 4.1.0, < 4.3.5

Published CVSS scores

8.6GitHub CNACVSS: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

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-23Relative Path Traversal
CWE-434Unrestricted Upload of File with Dangerous Type
T1105Ingress Tool Transfer

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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