CVE-2026-27966

CRITICALPre-NVD 9.89.8
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to the CVSS score beside it.

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, GitHub Security Advisory, a secondary CVSS source
Weaponized

Also known asEUVD-2026-8819 (ENISA EUVD) · GHSA-3645-fxcv-hqr4 (GitHub Security Advisories) · PYSEC-2026-376 (OSV.dev)Source: ENISA EUVD

9.8EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
  • Public exploit code is available (Metasploit, other public proof-of-concept code)
CISA-KEV: Not listedEPSS PROB: 35%CVSS: 9.8Exploit: Metasploit · other public PoCExposed services: Not assessed

The CVE record names the fixed release — apply it.

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
9.8CRITICALmedium confidence
EG Risk
85
EG Risk 85/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity98% × 45%
Impact severity (EG Severity): CVSS 9.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation65% × 40%
EchelonGraph's fixed weight for EG-KEV Tier 2 (Weaponized): a constant, not a probability.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low, Track* at medium and Attend at high mission impact.
Exploitation public PoC (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: The CVE record names the fixed release. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
35%
EPSS %ILE
98th
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (9.8): severity, escalated by confirmed exploitation. This CVE's 9.8 is its impact severity (EG Severity), not escalated.

EG Severity
9.8 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
35% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-12). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track* at medium mission impactTrack at low, Track* at medium and Attend at high mission impact.CISA BOD 26-04: 3 days if the affected system is publicly exposed; 60 days if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low, Track* at medium and Attend at high mission impact.

The CVE record names the fixed release. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation public PoC (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)3 days if the affected system is publicly exposed; 60 days if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

February 26, 2026

Last Modified

June 17, 2026

Advisory Details (2)

Auto-updated Oct 31, 2026
Fix named in the CVE record. Sources: github_commit, github.
GitHub advisoryMentions a patch (unverified)

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

Vendor Advisories for CVE-2026-27966(1)

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

Patch Availability(1)

Vendor / EcosystemFix (by version range) / 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 rangeFix by version rangeDependents
langflow0.0.31 ... 1.8.0rc2 (283 versions)
  • every version through 1.8.0rc2: no fix on record
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 14× in last 7d / 59× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed its CVE.org record (CNA or CISA ADP). An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). "EchelonGraph re-scored" is our own recompute of this CVE's score, not an update from a source, and is not counted in the refreshes above. Most recent first.

Showing the most recent 100 of 189 rows on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. None are among the latest 100 rows. The 89 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-13 16:51 UTCEPSS rescoreEPSS 35% · 98th percentile
  2. 2026-11-13 06:39 UTCEchelonGraph re-scored
  3. 2026-11-13 06:39 UTCGHSA enrichmentGHSA-3645-fxcv-hqr4 · GitHub severity CRITICAL · GitHub CVSS 9.8
  4. 2026-11-12 16:33 UTCEPSS rescoreEPSS 35% · 98th percentile
  5. 2026-11-12 06:28 UTCEchelonGraph re-scored
  6. 2026-11-12 06:28 UTCGHSA enrichmentGHSA-3645-fxcv-hqr4 · GitHub severity CRITICAL · GitHub CVSS 9.8
  7. 2026-11-11 16:39 UTCEPSS rescoreEPSS 35% · 98th percentile
  8. 2026-11-11 06:17 UTCEchelonGraph re-scored
  9. 2026-11-11 06:17 UTCGHSA enrichmentGHSA-3645-fxcv-hqr4 · GitHub severity CRITICAL · GitHub CVSS 9.8
  10. 2026-11-10 16:43 UTCEPSS rescoreEPSS 35% · 98th percentile
  11. 2026-11-10 06:05 UTCEchelonGraph re-scored
  12. 2026-11-10 06:05 UTCGHSA enrichmentGHSA-3645-fxcv-hqr4 · GitHub severity CRITICAL · GitHub CVSS 9.8
  13. 2026-11-09 16:35 UTCEPSS rescoreEPSS 35% · 98th percentile
  14. 2026-11-09 05:53 UTCEchelonGraph re-scored
  15. 2026-11-09 05:53 UTCGHSA enrichmentGHSA-3645-fxcv-hqr4 · GitHub severity CRITICAL · GitHub CVSS 9.8
  16. 2026-11-08 16:39 UTCEPSS rescoreEPSS 35% · 98th percentile
  17. 2026-11-08 05:43 UTCEchelonGraph re-scored
  18. 2026-11-08 05:43 UTCGHSA enrichmentGHSA-3645-fxcv-hqr4 · GitHub severity CRITICAL · GitHub CVSS 9.8
  19. 2026-11-07 16:38 UTCEPSS rescoreEPSS 35% · 98th percentile
  20. 2026-11-07 05:31 UTCEchelonGraph re-scored
  21. 2026-11-07 05:31 UTCGHSA enrichmentGHSA-3645-fxcv-hqr4 · GitHub severity CRITICAL · GitHub CVSS 9.8
  22. 2026-11-06 16:37 UTCEPSS rescoreEPSS 35% · 98th percentile
  23. 2026-11-06 05:20 UTCEchelonGraph re-scored
  24. 2026-11-06 05:20 UTCGHSA enrichmentGHSA-3645-fxcv-hqr4 · GitHub severity CRITICAL · GitHub CVSS 9.8
  25. 2026-11-06 04:55 UTCOSV refresh
Show 75 more
  1. 2026-11-05 16:37 UTCEPSS rescoreEPSS 35% · 98th percentile
  2. 2026-11-05 05:09 UTCEchelonGraph re-scored
  3. 2026-11-05 05:09 UTCGHSA enrichmentGHSA-3645-fxcv-hqr4 · GitHub severity CRITICAL · GitHub CVSS 9.8
  4. 2026-11-04 16:35 UTCEPSS rescoreEPSS 35% · 98th percentile
  5. 2026-11-04 04:58 UTCEchelonGraph re-scored
  6. 2026-11-04 04:58 UTCGHSA enrichmentGHSA-3645-fxcv-hqr4 · GitHub severity CRITICAL · GitHub CVSS 9.8
  7. 2026-11-03 16:47 UTCEPSS rescoreEPSS 35% · 98th percentile
  8. 2026-11-03 04:47 UTCEchelonGraph re-scored
  9. 2026-11-03 04:47 UTCGHSA enrichmentGHSA-3645-fxcv-hqr4 · GitHub severity CRITICAL · GitHub CVSS 9.8
  10. 2026-11-02 04:35 UTCEchelonGraph re-scored
  11. 2026-11-02 04:35 UTCGHSA enrichmentGHSA-3645-fxcv-hqr4 · GitHub severity CRITICAL · GitHub CVSS 9.8
  12. 2026-11-01 16:34 UTCEPSS rescoreEPSS 35% · 98th percentile
  13. 2026-11-01 04:24 UTCEchelonGraph re-scored
  14. 2026-11-01 04:24 UTCGHSA enrichmentGHSA-3645-fxcv-hqr4 · GitHub severity CRITICAL · GitHub CVSS 9.8
  15. 2026-10-31 16:32 UTCEPSS rescoreEPSS 35% · 98th percentile
  16. 2026-10-31 04:14 UTCEchelonGraph re-scored
  17. 2026-10-31 04:14 UTCGHSA enrichmentGHSA-3645-fxcv-hqr4 · GitHub severity CRITICAL · GitHub CVSS 9.8
  18. 2026-10-30 16:34 UTCEPSS rescoreEPSS 35% · 98th percentile
  19. 2026-10-30 03:57 UTCEchelonGraph re-scored
  20. 2026-10-30 03:57 UTCGHSA enrichmentGHSA-3645-fxcv-hqr4 · GitHub severity CRITICAL · GitHub CVSS 9.8
  21. 2026-10-29 16:33 UTCEPSS rescoreEPSS 35% · 98th percentile
  22. 2026-10-29 03:47 UTCEchelonGraph re-scored
  23. 2026-10-29 03:47 UTCGHSA enrichmentGHSA-3645-fxcv-hqr4 · GitHub severity CRITICAL · GitHub CVSS 9.8
  24. 2026-10-28 16:32 UTCEPSS rescoreEPSS 35% · 98th percentile
  25. 2026-10-28 03:34 UTCEchelonGraph re-scored
  26. 2026-10-28 03:34 UTCGHSA enrichmentGHSA-3645-fxcv-hqr4 · GitHub severity CRITICAL · GitHub CVSS 9.8
  27. 2026-10-27 16:31 UTCEPSS rescoreEPSS 35% · 98th percentile
  28. 2026-10-27 03:13 UTCEchelonGraph re-scored
  29. 2026-10-27 03:12 UTCGHSA enrichmentGHSA-3645-fxcv-hqr4 · GitHub severity CRITICAL · GitHub CVSS 9.8
  30. 2026-10-26 16:31 UTCEPSS rescoreEPSS 35% · 98th percentile
  31. 2026-10-25 22:58 UTCEchelonGraph re-scored
  32. 2026-10-25 22:58 UTCGHSA enrichmentGHSA-3645-fxcv-hqr4 · GitHub severity CRITICAL · GitHub CVSS 9.8
  33. 2026-10-25 16:32 UTCEPSS rescoreEPSS 35% · 98th percentile
  34. 2026-10-25 14:38 UTCEchelonGraph re-scored
  35. 2026-10-24 22:46 UTCEchelonGraph re-scored
  36. 2026-10-24 22:46 UTCGHSA enrichmentGHSA-3645-fxcv-hqr4 · GitHub severity CRITICAL · GitHub CVSS 9.8
  37. 2026-10-24 16:32 UTCEPSS rescoreEPSS 2.8% · 86th percentile
  38. 2026-10-23 22:36 UTCEchelonGraph re-scored
  39. 2026-10-23 22:35 UTCGHSA enrichmentGHSA-3645-fxcv-hqr4 · GitHub severity CRITICAL · GitHub CVSS 9.8
  40. 2026-10-23 16:31 UTCEPSS rescoreEPSS 2.5% · 84th percentile
  41. 2026-10-22 22:12 UTCEchelonGraph re-scored
  42. 2026-10-22 22:12 UTCGHSA enrichmentGHSA-3645-fxcv-hqr4 · GitHub severity CRITICAL · GitHub CVSS 9.8
  43. 2026-10-22 16:34 UTCEPSS rescoreEPSS 2.5% · 84th percentile
  44. 2026-10-21 21:49 UTCEchelonGraph re-scored
  45. 2026-10-21 21:49 UTCGHSA enrichmentGHSA-3645-fxcv-hqr4 · GitHub severity CRITICAL · GitHub CVSS 9.8
  46. 2026-10-21 16:32 UTCEPSS rescoreEPSS 2.5% · 84th percentile
  47. 2026-10-20 21:12 UTCEchelonGraph re-scored
  48. 2026-10-20 21:12 UTCGHSA enrichmentGHSA-3645-fxcv-hqr4 · GitHub severity CRITICAL · GitHub CVSS 9.8
  49. 2026-10-20 16:32 UTCEPSS rescoreEPSS 2.5% · 84th percentile
  50. 2026-10-19 21:00 UTCEchelonGraph re-scored
  51. 2026-10-19 21:00 UTCGHSA enrichmentGHSA-3645-fxcv-hqr4 · GitHub severity CRITICAL · GitHub CVSS 9.8
  52. 2026-10-19 16:31 UTCEPSS rescoreEPSS 2.5% · 84th percentile
  53. 2026-10-18 19:37 UTCEchelonGraph re-scored
  54. 2026-10-18 19:37 UTCGHSA enrichmentGHSA-3645-fxcv-hqr4 · GitHub severity CRITICAL · GitHub CVSS 9.8
  55. 2026-10-18 16:31 UTCEPSS rescoreEPSS 2.5% · 84th percentile
  56. 2026-10-18 03:50 UTCEchelonGraph re-scored
  57. 2026-10-17 19:24 UTCEchelonGraph re-scored
  58. 2026-10-17 19:24 UTCGHSA enrichmentGHSA-3645-fxcv-hqr4 · GitHub severity CRITICAL · GitHub CVSS 9.8
  59. 2026-10-17 16:33 UTCEPSS rescoreEPSS 2.5% · 84th percentile
  60. 2026-10-16 19:12 UTCEchelonGraph re-scored
  61. 2026-10-16 19:12 UTCGHSA enrichmentGHSA-3645-fxcv-hqr4 · GitHub severity CRITICAL · GitHub CVSS 9.8
  62. 2026-10-16 16:41 UTCEPSS rescoreEPSS 2.5% · 84th percentile
  63. 2026-10-15 16:31 UTCEPSS rescoreEPSS 2.5% · 84th percentile
  64. 2026-10-15 16:21 UTCEchelonGraph re-scored
  65. 2026-10-15 16:21 UTCGHSA enrichmentGHSA-3645-fxcv-hqr4 · GitHub severity CRITICAL · GitHub CVSS 9.8
  66. 2026-10-14 16:32 UTCEPSS rescoreEPSS 2.5% · 84th percentile
  67. 2026-10-14 10:33 UTCEchelonGraph re-scored
  68. 2026-10-14 10:32 UTCGHSA enrichmentGHSA-3645-fxcv-hqr4 · GitHub severity CRITICAL · GitHub CVSS 9.8
  69. 2026-10-13 16:34 UTCEPSS rescoreEPSS 2.5% · 84th percentile
  70. 2026-10-13 09:02 UTCEchelonGraph re-scored
  71. 2026-10-13 09:02 UTCGHSA enrichmentGHSA-3645-fxcv-hqr4 · GitHub severity CRITICAL · GitHub CVSS 9.8
  72. 2026-10-12 16:34 UTCEPSS rescoreEPSS 2.5% · 84th percentile
  73. 2026-10-12 16:17 UTCEchelonGraph re-scored
  74. 2026-10-12 08:48 UTCGHSA enrichmentGHSA-3645-fxcv-hqr4 · GitHub severity CRITICAL · GitHub CVSS 9.8
  75. 2026-10-11 19:59 UTCEchelonGraph re-scored

Publicly available exploits

(3 references)

Public exploit code is referenced for this CVE (1 Metasploit module, 2 GitHub PoCs). Defenders should treat patch urgency accordingly.

  • Metasploitexploit/multi/http/langflow_rce_cve_2026_27966✓ verified
    Published Apr 23, 2026

    Langflow RCE

    Open source ↗
  • GitHub PoCshinthink/CVE-2026-27966
    Published 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
    Published Mar 3, 2026

    Exploit Tools For new CVE

    Open source ↗

Frequently asked(5)

What is CVE-2026-27966?
CVE-2026-27966 is a critical-severity vulnerability; its CVE record was 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 allow_dangerous_code=True, which automatically exposes LangChain’s Python REPL tool (python_repl_ast). As a result, an attacker can execute arbitrary…
When was the CVE record for CVE-2026-27966 published?
The CVE record for CVE-2026-27966 was published on February 26, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of June 17, 2026; the record at its source may have been updated since.
Is CVE-2026-27966 actively exploited?
CVE-2026-27966 is not currently on CISA's Known Exploited Vulnerabilities catalog. EchelonGraph's EG-KEV model places it in Tier 2 (Weaponized), which is not evidence of exploitation: a Metasploit module exists for it. EchelonGraph does not test whether exploit code works. FIRST EPSS estimates a 35% probability of exploitation in the next 30 days (98th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-27966?
CVE-2026-27966 has a CVSS base score of 9.8 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-27966?
The CVE record for CVE-2026-27966 names the fix: "Version 1.8.0 fixes the issue." The vendor advisories EchelonGraph has for CVE-2026-27966 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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