CVE-2026-55255

Confirmed PUBLISHED

Langflow: IDOR Vulnerability in `/api/v1/responses` Endpoint Allows Authenticated Attackers to Access Another User's Flow

langflow-ai · langflow

Exploited in the wild Active exploitation observed PoC available

Recommended Action

Prioritize immediate patching and validate internet-facing exposure. Monitor for matching exploitation attempts in your environment.

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Confidence

Confirmed

Exploitation Status

Active exploitation observed

Observed in Sensors

Yes

Attempts (30d)

Unique Attacker IPs

CISA KEV

In CISA KEV

CVSS / EPSS

8.4 High EPSS 0.6%

At a Glance

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.

cisa

CVE Published: Jun 23, 2026
Exploitation Reported: Jul 07, 2026
CVSS: 8.4 High
EPSS: 0.6%

Remote No user interaction

Affected Versions

Vendor	Product	Version	Status
langflow-ai	langflow	< 1.9.1	Affected

CVE References

https://github.com/langflow-ai/langflow/security/advisories/GHSA-qrpv-q767-xqq2 github.com · CVE Record https://github.com/langflow-ai/langflow/security/advisories/GHSA-qrpv...
https://github.com/langflow-ai/langflow/pull/12832 github.com · CVE Record https://github.com/langflow-ai/langflow/pull/12832
https://github.com/langflow-ai/langflow/commit/2c9f498d664a3c32698b57d7c5e752625291060e github.com · CVE Record https://github.com/langflow-ai/langflow/commit/2c9f498d664a3c32698b57...

Recommended Actions

Prioritize immediate patching and validate internet-facing exposure. Monitor for matching exploitation attempts in your environment.
Review sensor telemetry for request paths, attacker IPs, and payload patterns that may inform detection and exposure validation.
Check enrichment artifacts for scanner coverage and available PoCs before rolling remediation validation.
Use the Pro API to automate enrichment, telemetry, and workflow delivery for VM, SOC, and CTI pipelines.

Known Exploited Vulnerability Sources

Catalogues that list this CVE as a known exploited vulnerability.

Per-source evidence links for KEV attestations are available through the KEVIntel Pro API.

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Source	Added
CISA First	2026-07-07 17:00 UTC
CVE	2026-07-07 18:20 UTC
All CISA Advisories	2026-07-07 19:20 UTC
KEVIntel	2026-07-13 01:45 UTC

Operational indicators for this CVE are listed on the Detection tab.

CVSS Scores

CVSS v3.1 8.4 High

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:L

Exploitation Status

Exploited in the wild

Recorded 2026-07-07 17:00:54 UTC · CISA

Active exploitation observed

Recorded 2026-07-13 01:43:28 UTC · KEVIntel sensor

Proof of concept available

Recorded 2026-06-30 14:49:22 UTC · GitHub

Weaknesses (CWE)

CWE-639

Authorization Bypass Through User-Controlled Key

Recent Mentions

CISA Adds Three Known Exploited Vulnerabilities to Catalog

All CISA Advisories · Jul 07, 2026

CISA has added three new vulnerabilities to its Known Exploited Vulnerabilities (KEV) Catalog, based on evidence of active exploitation. CVE-2026-48908 JoomShaper SP Page Builder Unrestricted Upload of File with Dangerous Type Vulnerability CVE-2026-55255 Langflow Authorization Bypass Through User-Controlled Key Vulnerability CVE-2026-56290 Joomlack Page Builder Improper Access Control Vulnerability These types of vulnerabilities are a frequent attack vector for malicious cyber actors and pose significant risks to the federal enterprise. Binding Operational Directive (BOD) 26-04: Prioritizing Security Updates Based on Risk establishes vulnerability management requirements for Federal Civilian Executive Branch (FCEB) agencies. BOD 26-04 reinforces the importance of the KEV Catalog and requires federal agencies to prioritize rapid remediation of high-risk vulnerabilities, specifically those identified by Common Vulnerabilities and Exposures (CVEs) listed in CISA’s KEV Catalog on publicly exposed assets that grant total control of the asset post-exploitation, while deferring action for lower-risk vulnerabilities. BOD 26-04 further establishes basic expectations for when agencies must check whether threat actors compromised the system before the patch was applied. While BOD 26-04 applies only to FCEB agencies, CISA encourages all organizations to adopt risk-based vulnerability management and prioritize remediation of KEV Catalog vulnerabilities. CISA will continue to add vulnerabilities to the catalog that meet the specified criteria. Aware of an exploited vulnerability not currently listed in the KEV Catalog? Submit it for potential addition through CISA’s KEV Nomination Form. Potential KEV additions must have a CVE ID, evidence of exploitation, and clear mitigation guidance.

Potential Proof of Concepts

These PoCs are unverified and could contain malware. Use at your own risk.

rootdirective-sec/CVE-2026-55255-Lab

github · Created 2026-06-30 14:49:22 UTC · 0 stars

Timeline

Key exploitation, disclosure, scanner coverage, and KEV attestation events for this CVE.

13 Jul 2026 01:43 UTC 6 days ago

13 Jul 2026 01:43 UTC · 6 days ago

Observed by KEVIntel sensors

Evidence-backed exploitation signal
13 Jul 2026 01:43 UTC 6 days ago

13 Jul 2026 01:43 UTC · 6 days ago

Indicators of compromise added (5)

Indicators of compromise recorded
7 Jul 2026 19:20 UTC 12 days ago

7 Jul 2026 19:20 UTC · 12 days ago

KEV confirmed by All CISA Advisories

Exploitation attested by an external source
7 Jul 2026 18:20 UTC 12 days ago

7 Jul 2026 18:20 UTC · 12 days ago

KEV confirmed by CVE

Exploitation attested by an external source
7 Jul 2026 17:00 UTC 12 days ago

7 Jul 2026 17:00 UTC · 12 days ago

Added to CISA KEV

Listed in the CISA Known Exploited Vulnerabilities catalog
30 Jun 2026 14:49 UTC 19 days ago

30 Jun 2026 14:49 UTC · 19 days ago

Public PoC available

Public proof-of-concept code published
23 Jun 2026 16:28 UTC 26 days ago

23 Jun 2026 16:28 UTC · 26 days ago

CVE published

Vulnerability disclosed publicly
16 Jun 2026 16:44 UTC about 1 month ago

16 Jun 2026 16:44 UTC · about 1 month ago

CVE ID reserved

Identifier reserved by the CNA

Automate This Intelligence with the Pro API

Confidence scoring, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.

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Pro API Example

GET /api/v2/pro/kevs/CVE-2026-55255

{
  "cve_id": "CVE-2026-55255",
  "title": "Langflow: IDOR Vulnerability in \`/api/v1/responses\` Endpoint Allows Authentic...",
  "affected_vendor": "langflow-ai",
  "affected_product": "langflow",
  "affected_versions": [
    { "vendor": "...", "product": "...", "status": "affected", "display_label": "..." }
  ],
  "confidence": "Confirmed",
  "cvss_score": 8.4,
  "epss_score": 0.0056,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": true
  },
  "sensor_telemetry": { "...": "Pro API fields" },
  "proof_of_concepts": [ "..." ],
  "scanner_integrations": [ "..." ]
}

The free JSON API returns basic KEV fields only. Confidence, telemetry, and artifact enrichment require Pro API access.

CVE-2026-55255

At a Glance

Affected Versions

CVE References

Recommended Actions

Known Exploited Vulnerability Sources

Observed Exploitation Attempts

Exploitation Attempts Over the Last 8 Days

See more exploitation detail

Indicators of Compromise (IoCs)

Observed Detection Signals (30d)

Virtual Patch

CVSS Scores

Exploitation Status

Weaknesses (CWE)

Recent Mentions

Potential Proof of Concepts

Timeline

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