CVE-2026-55255

CRITICALPre-NVD 8.49.0▲
EchelonGraph scoreHIGH confidence

Score elevated to 9.0 because this CVE is listed on the CISA Known Exploited Vulnerabilities catalog (added 2026-07-07), indicating real-world exploitation has been confirmed by US federal agencies. a secondary CVSS source baseline 8.4 retained for reference (NVD's own analysis pending). Confidence: HIGH.

Triggered by: CISA KEV (actively exploited)
Sources: cisa_kev, epss, secondary
Trending — 3 sources updated this weekExploited in the wild
9.0EG
EchelonGraph verdictPatch nowTreat as an emergency — this is being exploited.
  • Actively exploited in the wild (CISA-KEV)
CISA-KEV: ExploitedEPSS PROB: 1%CVSS: 8.4Exploit: cisa kev · ssvc activeExposed: 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 1.9.1, an Insecure Direct Object Reference (IDOR) vulnerability in /api/v1/responses endpoint allows an authenticated attacker to execute any flow belonging to another user by specifying the victim's flow ID in the request. This vulnerability is fixed in 1.9.1.

CVSS v3
8.4
EG Score
9.0(high)
EG Risk
81(Attend)
EG Risk 81/100SSVC: 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
Severity90% × 45%
Exploitation100% × 40%
Automatability0% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
1%
EPSS %ILE
58%
KEV
⚠ Exploited

Published

June 19, 2026

Last Modified

July 8, 2026

Advisory Details (2)

Auto-updated Jul 4, 2026
🔬 Proof of concept available. Patch available. Sources: github_pr, github.
github Patch Available🟡 PoC Available

IDOR Vulnerability in `/api/v1/responses` Endpoint Allows Authenticated Attackers to Access Another User's Flow · Advisory · langflow-ai/langflow · GitHub

https://github.com/langflow-ai/langflow/security/advisories/GHSA-qrpv-q767-xqq2
github_pr

fix(security): close IDOR in get_flow_by_id_or_endpoint_name (LE-639)

Fix merged in langflow-ai/langflow PR #12832 on 2026-04-22 — awaiting tagged release

https://github.com/langflow-ai/langflow/pull/12832

Vendor Advisories for CVE-2026-55255(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 ... 1.9.1 (295 versions)1.9.2—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 17× in last 7d / 71× 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 188 total refreshes for this CVE.

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

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Frequently asked(6)

What is CVE-2026-55255?
CVE-2026-55255 is a critical vulnerability published on June 19, 2026. Langflow is a tool for building and deploying AI-powered agents and workflows. Prior to 1.9.1, an Insecure Direct Object Reference (IDOR) vulnerability in /api/v1/responses endpoint allows an authenticated attacker to execute any flow belonging to another user by specifying the victim's flow ID in…
When was CVE-2026-55255 disclosed?
CVE-2026-55255 was first published in the National Vulnerability Database on June 19, 2026, with the most recent update on July 8, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-55255 actively exploited?
Yes. CISA added CVE-2026-55255 to the Known Exploited Vulnerabilities catalog on July 7, 2026, affecting Langflow Langflow. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate patching attention.
What is the CVSS score of CVE-2026-55255?
CVE-2026-55255 has a CVSS v3 base score of 8.4 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 9.0.
Which products are affected by CVE-2026-55255?
CVE-2026-55255 affects Langflow Langflow. The full affected-products list, including version ranges and fixed versions, is shown in the Affected Packages section of this page.
How do I remediate CVE-2026-55255?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-55255, 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

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