CVE-2026-33309

CRITICALPre-NVD 9.99.9—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.9 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 11.1%, top 4% 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
Elevated
9.9EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1.0%CVSS: 9.9Exploit: Elevated riskExposed services: Not assessed

A fix is available — apply it.

Langflow is a tool for building and deploying AI-powered agents and workflows. Versions 1.2.0 through 1.8.1 have a bypass of the patch for CVE-2025-68478 (External Control of File Name), leading to the root architectural issue within LocalStorageService remaining unresolved. Because the underlying storage layer lacks boundary containment checks, the system relies entirely on the HTTP-layer ValidatedFileName dependency. This defense-in-depth failure leaves the POST /api/v2/files/ endpoint vulnerable to Arbitrary File Write. The multipart upload filename bypasses the path-parameter guard, allowing authenticated attackers to write files anywhere on the host system, leading to Remote Code Execution (RCE). Version 1.9.0 contains an updated fix.

CVSS v3
9.9
EG Score
9.9CRITICALmedium confidence
EG Risk
61
EG Risk 61/100

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
Severity99% × 45%
Exploitation40% × 40%
Automatability0% × 15%
EPSS PROB
1.0%
EPSS %ILE
63rd
KEV
Not listed

Published

March 19, 2026

Last Modified

June 17, 2026

Advisory Details (1)

Auto-updated Oct 5, 2026
🔬 Proof of concept available. Patch available. Sources: github.
githubMentions a patch (unverified)🟡 PoC Available

Arbitrary File Write (RCE) via v2 API · Advisory · langflow-ai/langflow · GitHub

https://github.com/langflow-ai/langflow/security/advisories/GHSA-g2j9-7rj2-gm6c

Vendor Advisories for CVE-2026-33309(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 rangeFix by version rangeDependents
langflow1.2.0 ... 1.8.4 (41 versions)
  • 1.2.0 up to 1.9.0: fixed in 1.9.0
—

Weakness Classification(4)

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

Data Freshness Timeline

(refreshed 7× in last 7d / 25× 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.

Showing the most recent 100 of 153 total refreshes for this CVE.

  1. 2026-10-10 20:00 UTCEPSS rescore
  2. 2026-10-09 20:07 UTCEPSS rescore
  3. 2026-10-08 17:12 UTCEPSS rescore
  4. 2026-10-07 23:47 UTCEPSS rescore
  5. 2026-10-06 15:17 UTCEPSS rescore
  6. 2026-10-05 17:42 UTCEPSS rescore
  7. 2026-10-04 23:22 UTCEPSS rescore
  8. 2026-10-03 14:25 UTCEPSS rescore
  9. 2026-10-01 19:49 UTCEPSS rescore
  10. 2026-09-30 15:03 UTCEPSS rescore
  11. 2026-09-28 13:51 UTCEPSS rescore
  12. 2026-09-27 13:48 UTCEPSS rescore
  13. 2026-09-26 15:58 UTCEPSS rescore
  14. 2026-09-26 00:26 UTCEPSS rescore
  15. 2026-09-21 21:31 UTCOSV refresh
  16. 2026-09-20 20:15 UTCEPSS rescore
  17. 2026-09-18 19:28 UTCEPSS rescore
  18. 2026-09-18 19:28 UTCEPSS rescore
  19. 2026-09-17 19:30 UTCEPSS rescore
  20. 2026-09-16 14:08 UTCEPSS rescore
  21. 2026-09-16 05:15 UTCEPSS rescore
  22. 2026-09-15 03:11 UTCEPSS rescore
  23. 2026-09-12 15:01 UTCEPSS rescore
  24. 2026-09-11 14:53 UTCEPSS rescore
  25. 2026-09-11 09:37 UTCEPSS rescore
Show 75 more
  1. 2026-09-10 09:34 UTCEPSS rescore
  2. 2026-09-08 22:00 UTCEPSS rescore
  3. 2026-09-07 16:01 UTCEPSS rescore
  4. 2026-09-06 13:47 UTCEPSS rescore
  5. 2026-09-06 13:47 UTCEPSS rescore
  6. 2026-09-04 05:06 UTCEPSS rescore
  7. 2026-09-02 17:38 UTCOSV refresh
  8. 2026-09-02 14:11 UTCEPSS rescore
  9. 2026-09-01 13:53 UTCEPSS rescore
  10. 2026-09-01 04:39 UTCEPSS rescore
  11. 2026-09-01 04:39 UTCEPSS rescore
  12. 2026-08-30 19:17 UTCEPSS rescore
  13. 2026-08-30 01:22 UTCEPSS rescore
  14. 2026-08-28 21:41 UTCEPSS rescore
  15. 2026-08-27 14:25 UTCEPSS rescore
  16. 2026-08-26 14:46 UTCEPSS rescore
  17. 2026-08-25 13:49 UTCEPSS rescore
  18. 2026-08-24 14:17 UTCEPSS rescore
  19. 2026-08-23 00:19 UTCEPSS rescore
  20. 2026-08-21 23:49 UTCEPSS rescore
  21. 2026-08-20 22:55 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. 2026-08-17 13:47 UTCEPSS rescore
  26. 2026-08-16 14:56 UTCEPSS rescore
  27. 2026-08-16 11:10 UTCEG score recompute
  28. 2026-08-16 02:14 UTCEPSS rescore
  29. 2026-08-15 01:30 UTCEPSS rescore
  30. 2026-08-14 07:20 UTCEG score recompute
  31. 2026-08-13 22:00 UTCEPSS rescore
  32. 2026-08-12 22:05 UTCEG score recompute
  33. 2026-08-12 13:50 UTCEPSS rescore
  34. 2026-08-11 21:28 UTCEG score recompute
  35. 2026-08-11 04:32 UTCEG score recompute
  36. 2026-08-11 00:00 UTCEPSS rescore
  37. 2026-08-09 17:34 UTCEG score recompute
  38. 2026-08-09 13:46 UTCEPSS rescore
  39. 2026-08-09 06:54 UTCEG score recompute
  40. 2026-08-08 16:37 UTCEPSS rescore
  41. 2026-08-07 17:24 UTCEG score recompute
  42. 2026-08-06 19:26 UTCEG score recompute
  43. 2026-08-06 13:46 UTCEPSS rescore
  44. 2026-08-06 01:34 UTCEG score recompute
  45. 2026-08-05 19:17 UTCEPSS rescore
  46. 2026-08-04 15:10 UTCEPSS rescore
  47. 2026-08-04 10:38 UTCEPSS rescore
  48. 2026-08-02 16:35 UTCEG score recompute
  49. 2026-08-02 02:27 UTCEPSS rescore
  50. 2026-08-01 04:16 UTCEPSS rescore
  51. 2026-07-30 16:28 UTCEPSS rescore
  52. 2026-07-30 01:30 UTCEPSS rescore
  53. 2026-07-26 14:54 UTCEPSS rescore
  54. 2026-07-26 14:54 UTCEPSS rescore
  55. 2026-07-25 14:18 UTCEPSS rescore
  56. 2026-07-25 14:18 UTCEPSS rescore
  57. 2026-07-24 14:17 UTCEPSS rescore
  58. 2026-07-24 14:17 UTCEPSS rescore
  59. 2026-07-23 14:18 UTCEPSS rescore
  60. 2026-07-23 14:18 UTCEPSS rescore
  61. 2026-07-23 03:09 UTCEG score recompute
  62. 2026-07-22 14:08 UTCEPSS rescore
  63. 2026-07-21 15:24 UTCEPSS rescore
  64. 2026-07-20 17:08 UTCEPSS rescore
  65. 2026-07-19 14:31 UTCEPSS rescore
  66. 2026-07-19 02:29 UTCEPSS rescore
  67. 2026-07-18 10:04 UTCEPSS rescore
  68. 2026-07-17 14:59 UTCOSV refresh
  69. 2026-07-16 17:03 UTCEPSS rescore
  70. 2026-07-15 16:57 UTCEPSS rescore
  71. 2026-07-15 16:57 UTCEPSS rescore
  72. 2026-07-15 02:00 UTCEPSS rescore
  73. 2026-07-15 02:00 UTCEPSS rescore
  74. 2026-07-13 22:30 UTCEPSS rescore
  75. 2026-07-13 06:13 UTCEPSS rescore

Related CVEs(same product + same CWE)

Frequently asked(5)

What is CVE-2026-33309?
CVE-2026-33309 is a critical vulnerability published on March 19, 2026. Langflow is a tool for building and deploying AI-powered agents and workflows. Versions 1.2.0 through 1.8.1 have a bypass of the patch for CVE-2025-68478 (External Control of File Name), leading to the root architectural issue within LocalStorageService remaining unresolved. Because the underlying…
When was CVE-2026-33309 disclosed?
CVE-2026-33309 was first published on March 19, 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-2026-33309 actively exploited?
CVE-2026-33309 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1.0% probability of exploitation in the next 30 days (63rd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-33309?
CVE-2026-33309 has a CVSS base score of 9.9 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-33309?
A fix for CVE-2026-33309 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-33309 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-33309

Explore →

Is Your Infrastructure Affected by CVE-2026-33309?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Book a Demo →Browse All CVEs