CVE-2026-42867

MEDIUMPre-NVD 6.56.5—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 6.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.5%, top 62% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
6.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.5Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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.

CVSS v3
6.5
EG Score
6.5(medium)
EG Risk
34(Track)
EG Risk 34/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity65% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
38%
KEV
Not listed

Published

June 16, 2026

Last Modified

June 26, 2026

Advisory Details (2)

Auto-updated Jun 23, 2026
🔬 Proof of concept available. Patch available. Sources: github_pr, github.
github Patch Available🟡 PoC Available

Path Traversal in Knowledge Bases API via Creation Endpoint · Advisory · langflow-ai/langflow · GitHub

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

fix: prevent path traversal in knowledge base create endpoint

Fix merged in langflow-ai/langflow PR #12337 on 2026-03-26 — awaiting tagged release

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

Vendor Advisories for CVE-2026-42867(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(1 across 1 ecosystem)
PyPI(1)
PackageVulnerable rangeFixed inDependents
langflow0.0.31 ... 1.8.4 (293 versions)1.9.0—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 9× in last 7d / 50× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-08-26 14:46 UTCEPSS rescore
  2. 2026-08-25 13:49 UTCEPSS rescore
  3. 2026-08-24 23:24 UTCEG score recompute
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  1. 2026-08-11 00:00 UTCEPSS rescore
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  3. 2026-08-09 13:46 UTCEPSS rescore
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  5. 2026-08-08 16:37 UTCEPSS rescore
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  34. 2026-07-23 03:12 UTCEG score recompute
  35. 2026-07-22 14:08 UTCEPSS rescore
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  38. 2026-07-19 14:31 UTCEPSS rescore
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  48. 2026-07-09 19:10 UTCEPSS rescore
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  65. 2026-06-24 14:05 UTCEPSS rescore
  66. 2026-06-16 17:46 UTCEG score recompute

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-42867?
CVE-2026-42867 is a medium vulnerability published on June 16, 2026. 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…
When was CVE-2026-42867 disclosed?
CVE-2026-42867 was first published in the National Vulnerability Database on June 16, 2026, with the most recent update on June 26, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-42867 actively exploited?
CVE-2026-42867 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 61.5% of all scored CVEs.
What is the CVSS score of CVE-2026-42867?
CVE-2026-42867 has a CVSS v3 base score of 6.5 (NVD).
How do I remediate CVE-2026-42867?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-42867, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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