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Public proof of concept

CVE-2026-51888

Directory Traversal Allowing Arbitrary File Write in Langflow Knowledge Base Creation Endpoint

A public proof of concept exists; no exploitation attested.

  • Published2026-10-01
  • WeaknessCWE-22

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

langflow-ai langflow v1.8.4 is affected by: Directory Traversal. The impact is: Arbitrary file write outside the intended workspace or storage boundary.. The component is: src/backend/base/langflow/api/v1/knowledge_bases.py:knowledge_bases-create_knowledge_base-a-live-http-post-to-create-knowledge-base. The attack vector is: Attack surface: HTTP or browser-backed service path. A public-facing upload or HTTP route handler forwards an attacker-controlled path or filename into host file creation without any visible boundary enforcement. ¶¶ A weakness has been identified in langflow-ai langflow up to 1.8.4. langflow contains an absolute path traversal vulnerability in knowledge_bases-create_knowledge_base-a-live-http-post-to-create-knowledge-base (src/backend/base/langflow/api/v1/knowledge_bases.py:51). An attacker can write or overwrite files outside the intended working directory by providing absolute paths in the knowledge base creation endpoint.

Timeline

dates in UTC
  1. 2026-10-0122:17CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 15:37 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2026-51888?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2026-51888?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

Neither OSV.dev nor the vendor advisories we read list affected versions for CVE-2026-51888 yet.

Full record on NVD

Fix

No fix published by the sources we read yet. NVD record

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
none listed
PoC-in-GitHub

Sources

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Published
2026-10-01
Last Modified
2026-10-06
NVD status
Awaiting Analysis

Frequently asked questions

What is CVE-2026-51888?

langflow-ai langflow v1.8.4 is affected by: Directory Traversal. The impact is: Arbitrary file write outside the intended workspace or storage boundary.. The component is: src/backend/base/langflow/api/v1/knowledge_bases.py:knowledge_bases-create_knowledge_base-a-live-http-post-to-create-knowledge-base. The attack vector is: Attack surface: HTTP or browser-backed service path. A public-facing upload or HTTP route handler forwards an attacker-controlled path or filename into host file creation without any visible boundary enforcement. ¶¶ A weakness has been identified in langflow-ai langflow up to 1.8.4. langflow contains an absolute path traversal vulnerability in knowledge_bases-create_knowledge_base-a-live-http-post-to-create-knowledge-base (src/backend/base/langflow/api/v1/knowledge_bases.py:51). An attacker can write or overwrite files outside the intended working directory by providing absolute paths in the knowledge base creation endpoint.

Is CVE-2026-51888 actively exploited?

A proof-of-concept exploit exists for CVE-2026-51888, but active exploitation has not been confirmed at this time.

What is the CVSS score for CVE-2026-51888?

CVE-2026-51888 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.

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