CVE-2026-55255

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: 0.2%, top 86% 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
9.9
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 9.9Exploit: NoneExposed: 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 1.9.2, 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 1.9.2.

CVSS v3
9.9
EG Score
9.9(medium)
EPSS
14.2%
KEV
Not listed

Published

June 19, 2026

Last Modified

June 24, 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 ... 1.9.0 (294 versions)1.9.1—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 52× in last 7d / 127× 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 127 total refreshes for this CVE.

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Frequently asked(5)

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 1.9.2, 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 June 24, 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?
CVE-2026-55255 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 14.2% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-55255?
CVE-2026-55255 has a CVSS v3 base score of 9.9 (NVD).
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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