CVE-2026-42867

MEDIUM 6.5 PoC AVAILABLE

Published 2026-06-23 · Last modified 2026-06-23

Langflow is a tool for building and deploying AI-powered agents and workflows. Prior to 1.9.0, Langflow is vulnerable to Path Traversal in the Knowledge Bases API (POST /api/v1/knowledge_bases). This occurs because user-supplied knowledge base names are used directly to create file paths without proper sanitization or containment checks. An authenticated attacker can exploit this flaw to create directories and write files anywhere on the server's filesystem. This vulnerability is fixed in 1.9.0.

EXPLOIT AVAILABLE

Public exploit or PoC code exists. Modeled probability is still low, but the barrier to attack is reduced — watch closely.

Exploitation likelihood

0.3%chance of exploitation in 30 days · 23rd percentile

○ In CISA KEV ● Public exploit / PoC

Impact if exploited

6.5CVSS 3.1 · MEDIUM

ConfidentialityNone
IntegrityLow
AvailabilityLow

What an attacker needs

✓Access: Reachable over the network — no local access needed
✓Privileges: No account or privileges required
✓User interaction: No user interaction needed
✓Complexity: No special conditions — reliably repeatable

✓ lowers the bar for an attacker · ⚠ raises it

Proof of concept & exploit code

reference https://github.com/langflow-ai/langflow/security/advisories/GHSA-79ph-745m-6wxq
github-search Search GitHub for public PoC repos

Test against your own equipment

curl -s https://vulnpedia.com/cve/CVE-2026-42867/poc.jsonMachine-readable PoC index for this CVE (for automation).

Listed for defensive triage, patch verification, and authorized testing on systems you own. Machine-readable: /cve/CVE-2026-42867/poc.json

Affected

Vendors Langflow Ai Langflow

Products Langflow

Weakness (CWE)

CWE-22: : Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L

Known Affected Software Configurations

Vendor	Product	Version range
Langflow	Langflow	< 1.9.0

All CVSS metrics

MEDIUM 6.5 v3.1 · CNA Primary
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L
MEDIUM 6.5 v3.1 · NVD Secondary
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L

References

Exploits & PoC

https://github.com/langflow-ai/langflow/security/advisories/GHSA-79ph-745m-6wxq x_refsource_CONFIRMexploitExploitVendor Advisory

Patches & mitigations

https://github.com/langflow-ai/langflow/pull/12337 x_refsource_MISCPatchIssue Tracking

Sources: NVD · CVE.org · EPSS