CVE-2026-27966

CRITICALPre-NVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-02-27. a secondary CVSS source baseline 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Weaponized
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.

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.

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 computed
Severity98% × 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 Sep 14, 2026
🔬 Proof of concept available. Patch available. Sources: github_commit, github.
github 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-hqr4
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/d8c6480daa17b2f2af0b5470cdf5c3d28dc9e508

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
piplangflow—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.

Affected Packages

(1 across 1 ecosystem)
PyPI(1)
PackageVulnerable rangeFixed inDependents
langflow0.0.31 ... 1.8.0rc2 (283 versions)——

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 5× in last 7d / 22× 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. 2026-09-18 19:28 UTCEPSS rescore
  2. 2026-09-18 19:27 UTCEPSS rescore
  3. 2026-09-17 19:30 UTCEPSS rescore
  4. 2026-09-16 14:08 UTCEPSS rescore
  5. 2026-09-16 05:15 UTCEPSS rescore
  6. 2026-09-12 15:01 UTCEPSS rescore
  7. 2026-09-11 14:52 UTCEPSS rescore
  8. 2026-09-10 09:34 UTCEPSS rescore
  9. 2026-09-08 22:00 UTCEPSS rescore
  10. 2026-09-06 13:47 UTCEPSS rescore
  11. 2026-09-06 13:47 UTCEPSS rescore
  12. 2026-09-04 05:06 UTCEPSS rescore
  13. 2026-09-02 14:11 UTCEPSS rescore
  14. 2026-09-01 01:04 UTCOSV refresh
  15. 2026-08-30 19:17 UTCEPSS rescore
  16. 2026-08-30 01:22 UTCEPSS rescore
  17. 2026-08-28 21:41 UTCEPSS rescore
  18. 2026-08-26 14:46 UTCEPSS rescore
  19. 2026-08-25 13:49 UTCEPSS rescore
  20. 2026-08-23 00:19 UTCEPSS rescore
  21. 2026-08-21 23:49 UTCEPSS rescore
  22. 2026-08-20 22:55 UTCEPSS rescore
  23. 2026-08-19 17:03 UTCEPSS rescore
  24. 2026-08-18 13:48 UTCEPSS rescore
  25. 2026-08-16 14:56 UTCEPSS rescore
Show 46 more
  1. 2026-08-16 02:14 UTCEPSS rescore
  2. 2026-08-15 01:30 UTCEPSS rescore
  3. 2026-08-15 01:05 UTCGHSA enrichment
  4. 2026-08-14 21:10 UTCGHSA enrichment
  5. 2026-08-14 12:52 UTCGHSA enrichment
  6. 2026-08-14 08:57 UTCEG score recompute
  7. 2026-08-14 08:57 UTCGHSA enrichment
  8. 2026-08-13 22:00 UTCEPSS rescore
  9. 2026-08-13 04:51 UTCGHSA enrichment
  10. 2026-08-13 00:57 UTCEG score recompute
  11. 2026-08-13 00:57 UTCGHSA enrichment
  12. 2026-08-12 13:50 UTCEPSS rescore
  13. 2026-08-11 23:52 UTCEG score recompute
  14. 2026-08-11 23:51 UTCGHSA enrichment
  15. 2026-08-11 13:42 UTCEPSS rescore
  16. 2026-08-11 06:16 UTCGHSA enrichment
  17. 2026-08-10 13:13 UTCGHSA enrichment
  18. 2026-08-10 08:43 UTCGHSA enrichment
  19. 2026-08-10 01:34 UTCGHSA enrichment
  20. 2026-08-09 21:39 UTCGHSA enrichment
  21. 2026-08-09 17:45 UTCGHSA enrichment
  22. 2026-08-09 13:48 UTCGHSA enrichment
  23. 2026-08-09 08:35 UTCGHSA enrichment
  24. 2026-08-08 08:21 UTCGHSA enrichment
  25. 2026-08-08 04:26 UTCGHSA enrichment
  26. 2026-08-08 00:32 UTCGHSA enrichment
  27. 2026-08-07 20:37 UTCEG score recompute
  28. 2026-08-07 20:37 UTCGHSA enrichment
  29. 2026-08-06 13:46 UTCEPSS rescore
  30. 2026-08-06 06:53 UTCGHSA enrichment
  31. 2026-08-06 02:58 UTCEG score recompute
  32. 2026-08-06 02:58 UTCGHSA enrichment
  33. 2026-08-05 19:17 UTCEPSS rescore
  34. 2026-08-04 15:10 UTCEPSS rescore
  35. 2026-08-04 05:00 UTCGHSA enrichment
  36. 2026-08-02 23:26 UTCGHSA enrichment
  37. 2026-08-02 19:30 UTCEG score recompute
  38. 2026-08-02 19:30 UTCGHSA enrichment
  39. 2026-08-02 02:26 UTCEPSS rescore
  40. 2026-08-01 04:16 UTCEPSS rescore
  41. 2026-07-30 16:27 UTCEPSS rescore
  42. 2026-07-30 01:30 UTCEPSS rescore
  43. 2026-07-28 15:36 UTCEPSS rescore
  44. 2026-07-27 12:54 UTCEG score recompute
  45. 2026-07-27 12:54 UTCGHSA enrichment
  46. 2026-07-27 12:50 UTCOSV refresh

Publicly available exploits

(3 references)

Working exploit code is in the public domain (1 Metasploit module) (2 GitHub PoCs). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • GitHub PoCshinthink/CVE-2026-27966
    First seen Jul 5, 2026

    Pre-auth RCE scanner for Langflow < 1.8.0 — Route Injection + Vertex Injection → Code Execution (CVSS 9.8)

    Open source ↗
  • GitHub PoCAnon-Cyber-Team/CVE-2026-27966--RCE-in-Langflow
    First seen Mar 3, 2026

    Exploit Tools For new CVE

    Open source ↗
  • Metasploitexploit/multi/http/langflow_rce_cve_2026_27966✓ verified
    First seen Feb 25, 2026

    Langflow RCE

    Open source ↗

Related CVEs(same product + same CWE)

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 1.7% 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

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-27966

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