What is CVE-2026-55255?
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.
The record classifies CVE-2026-55255 under weakness class CWE-639. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs low-privilege credentials, needs no user interaction, and has high impact on confidentiality, integrity. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 104 days ago.
Severity and exploitation probability
- CVSS v3.1 base score
- 9.9 — CRITICAL
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:L - EPSS (FIRST)
- 0.2% probability of exploitation in the next 30 days, higher than 14.0% of all scored CVEs
- CISA KEV
- Not listed in the CISA Known Exploited Vulnerabilities catalog
- Threadlinqs priority
- 5.5/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- Published
- 2026-06-23, last modified 2026-06-24
Is CVE-2026-55255 being exploited?
It currently carries a trending score of 33 in the Threadlinqs vulnerability feed.
Affected products and versions
- langflow-ai: langflow
Affected software packages:
pip:langflow— patched in 1.9.1
How to fix CVE-2026-55255
The record marks a vendor fix as available for CVE-2026-55255. Fixed versions are recorded for 1 package: pip:langflow 1.9.1. Patch reference: https://github.com/langflow-ai/langflow/pull/12832. Vendor advisory: https://github.com/langflow-ai/langflow/security/advisories/GHSA-qrpv-q767-xqq2. Apply the vendor fix referenced above to every affected product listed in this record, then confirm the running version against the vendor advisory.
Threat activity tracking CVE-2026-55255
1 tracked threat in the Threadlinqs corpus references CVE-2026-55255, either in the campaign’s CVE list or as an indicator on the campaign record.
Sources
Enriched from CVE.org, NVD, FIRST EPSS, GitHub Security Advisories. Last verified by Threadlinqs on . This product uses the NVD API but is not endorsed or certified by the NVD.