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Known exploited vulnerability

CVE-2026-55255

highCVSS 3.1 8.4In CISA KEVEPSS 0.89%Published · langflow-ai

The short answer

CVE-2026-55255 affects langflow-ai langflow and is rated high (CVSS 8.4). CISA added it to the Known Exploited Vulnerabilities catalog on 2026-07-07: attackers are using it, so patch it first. Fixed versions are published for langflow (1.9.1).

What it is

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.

Weakness: CWE-639.

Severity

8.4 high

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

Exploited (CISA KEV)

Yes, since Jul 7, 2026

Federal due date Jul 10, 2026

EPSS, next 30 days

0.89%

Higher than 60% of scored CVEs

How it can be exploited

Attack vector
Network
Attack complexity
High
Privileges required
Low
User interaction
None
Scope
Changed
Confidentiality impact
High
Integrity impact
High
Availability impact
Low

What CISA says to do

Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for…

Affected packages and fixed versions

PackageEcosystemFixed inAdvisory
langflowPyPI1.9.1GHSA-qrpv-q767-xqq2

Is it in your code? Drop your lockfile into the free vulnerability check, or let vulnerability watch check your repository every day and open the upgrade as a pull request.

Affected products

langflow. NVD's record lists the exact affected versions.

References

Questions

Is CVE-2026-55255 being exploited?

Yes. CISA added CVE-2026-55255 to its Known Exploited Vulnerabilities catalog on 2026-07-07, with a federal remediation due date of 2026-07-10.

How do I fix CVE-2026-55255?

Upgrade to a fixed version: langflow (PyPI) 1.9.1. CISA's required action: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for…

From NVD, CISA KEV, FIRST EPSS and OSV.dev, checked . Status on NVD: Analyzed. The description is NVD's text, quoted as published.

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