CVE-2026-42867 json
Langflow: Path Traversal in Knowledge Bases API via Creation Endpoint
published 4mo ago modified 14d ago also EUVD-2026-38518 , GHSA-79ph-745m-6wxq , PYSEC-2026-2566
- cvss
- 6.5
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.5%
- EPSS 0.5% chance of exploitation in 30 days, percentile 40%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- pypi langflow 1.9.0
- langflow langflow 1.9.0
- langflow-ai langflow 1.9.0
- github.com/langflow-ai/langflow#12337 pull request
Is CVE-2026-42867 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerCISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 4mo ago
Exploit prediction
0.47% chance of exploitation in the next 30 days, higher than 40% of all scored CVEs (FIRST EPSS, 2026-11-09).
Exploits and checks
- github.com https://github.com/langflow-ai/langflow/security/advisories/GHSA-79ph-745m-6wxq referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 6.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L |
| GitHub | 3.1 | 6.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L |
| OSV | 3.1 | 6.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| pypi | langflow | <1.9.0 |
1.9.0 |
Affected products
- langflow-ai langflow
Classification
- Weakness
-
- CWE-22 Improper Limitation of a Pathname to a Restricted Directory
References
-
github.com
/langflow-ai/langflow/pull/12337
web, patch, issue-tracking
-
github.com
/langflow-ai/langflow/security/advisories/GHSA-79ph-745m-6wxq
exploit, web, vendor-advisory
-
nvd.nist.gov
/vuln/detail/CVE-2026-42867
advisory
-
github.com
/advisories/GHSA-79ph-745m-6wxq
advisory
-
github.com
/langflow-ai/langflow
package
-
github.com
/pypa/advisory-database/tree/main/vulns/langflow/PYSEC-2026-2566.yaml
web
-
pypi.org
/project/langflow
web, package
Sources
- CVE List CVE-2026-42867
- GitHub Advisory GHSA-79ph-745m-6wxq
- NVD CVE-2026-42867
- OSV PYSEC-2026-2566
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.