Langflow is a tool for building and deploying AI-powered agents and workflows. Prior to version 1.8.0, the CSV Agent node in Langflow hardcodes allow_dangerous_code=True, which automatically exposes LangChain’s Python REPL tool (python_repl_ast). As a result, an attacker can execute arbitrary Python and OS commands on the server via prompt injection, leading to full Remote Code Execution (RCE). Version 1.8.0 fixes the issue.
CVE-2026-27966
CRITICALPre-NVD 9.89.8—Trending — 4 sources updated this weekWeaponized
EchelonGraph scoreMEDIUM confidence
Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-02-27. the CNA's CVSS baseline 9.8; sources differ by 0.0.
Triggered by: GitHub Security Advisory CVSS
Sources: cna:github_m, ghsa
9.8EG
EchelonGraph verdictPatch this weekExploitation is likely or a public exploit exists.
- Public exploit code is available (Metasploit, ssvc poc, epss top5pct, public exploit)
CISA-KEV: Not listedEPSS PROB: 34%CVSS: 9.8Exploit: Metasploit · ssvc poc · epss top5pct · public exploitExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 9.8
- EG Score
- 9.8(medium)
- EG Risk
- 85(Attend)EG Risk 85/100SSVC: Attend
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 computedSeverity98% × 45%Exploitation65% × 40%Automatability100% × 15%Action: Remediate soon — notable exploitation risk. - EPSS PROB
- 34%
- EPSS %ILE
- 98%
- KEV
- Not listed
Published
February 26, 2026
Last Modified
June 17, 2026
Advisory Details (2)
Auto-updated Jul 27, 2026🔬 Proof of concept available. Patch available. Sources: github, github_commit.
github_commit
commit d8c6480daa17 (langflow-ai/langflow)
Fix landed in langflow-ai/langflow commit d8c6480daa17 — awaiting tagged release
https://github.com/langflow-ai/langflow/commit/d8c6480daa17b2f2af0b5470cdf5c3d28dc9e508github Patch Available🟡 PoC Available
Remote Code Execution in CSV Agent · Advisory · langflow-ai/langflow · GitHub
https://github.com/langflow-ai/langflow/security/advisories/GHSA-3645-fxcv-hqr4Patch Availability(1)
| Vendor / Ecosystem | Fixed in / Patch | Released | Source |
|---|---|---|---|
| pip | langflow | — | ghsa |
Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 7× in last 7d / 7× 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.
- 2026-08-01 04:16 UTCEPSS rescore
- 2026-07-30 16:27 UTCEPSS rescore
- 2026-07-30 01:30 UTCEPSS rescore
- 2026-07-28 15:36 UTCEPSS rescore
- 2026-07-27 12:54 UTCEG score recompute
- 2026-07-27 12:54 UTCGHSA enrichment
- 2026-07-27 12:50 UTCOSV refresh
Publicly available exploits
(2 references)Working exploit code is in the public domain (1 Metasploit module) (1 GitHub PoC). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.
- GitHub PoCshinthink/CVE-2026-27966First seen Jul 5, 2026
Pre-auth RCE scanner for Langflow < 1.8.0 — Route Injection + Vertex Injection → Code Execution (CVSS 9.8)
Open source ↗ - Metasploitexploit/multi/http/langflow_rce_cve_2026_27966✓ verifiedFirst seen Feb 25, 2026
Langflow RCE
Open source ↗
Related CVEs(same product + same CWE)
Same product
8 shownpip:langflow
Same CWE
10 shownCWE-94
- CVE-2003-1432EG 10.0EPSS p94HIGH
- CVE-2002-0495EG 10.0EPSS p96HIGH
- CVE-1999-0702EG 10.0EPSS p98HIGH
- CVE-1999-0509EG 10.0EPSS p98HIGH
- CVE-2006-1318EG 9.3EPSS p96HIGH
- CVE-2006-1301EG 9.3EPSS p95HIGH
- CVE-2006-1308EG 9.3EPSS p95HIGH
- CVE-2006-1309EG 9.3EPSS p95HIGH
- CVE-2006-1304EG 9.3EPSS p95HIGH
- CVE-2006-1306EG 9.3EPSS p95HIGH
Frequently asked(5)
What is CVE-2026-27966?
CVE-2026-27966 is a critical vulnerability published on February 26, 2026. Langflow is a tool for building and deploying AI-powered agents and workflows. Prior to version 1.8.0, the CSV Agent node in Langflow hardcodes allowdangerouscode=True, which automatically exposes LangChain’s Python REPL tool (pythonreplast). As a result, an attacker can execute arbitrary Python…
When was CVE-2026-27966 disclosed?
CVE-2026-27966 was first published in the National Vulnerability Database on February 26, 2026, with the most recent update on June 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-27966 actively exploited?
CVE-2026-27966 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 34% probability of exploitation in the next 30 days, which ranks it in the top 1.8% of all scored CVEs.
What is the CVSS score of CVE-2026-27966?
CVE-2026-27966 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2026-27966?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-27966, 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.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-27966
Is Your Infrastructure Affected by CVE-2026-27966?
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