CVE-2026-55255
HIGH 8.4 KNOWN EXPLOITED PoC AVAILABLELangflow 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.
ACTIVELY EXPLOITED
Confirmed exploited in the wild — in CISA KEV since 2026-07-07. Patch or mitigate now.
Exploitation likelihood
0.6%chance of exploitation in 30 days · 43rd percentile
● In CISA KEV (2026-07-07)
● Public exploit / PoC
Impact if exploited
8.4CVSS 3.1 · HIGH
- ConfidentialityHigh
- IntegrityHigh
- AvailabilityLow
What an attacker needs
- ✓Access: Reachable over the network — no local access needed
- ⚠Privileges: Requires a low-privilege account
- ✓User interaction: No user interaction needed
- ⚠Complexity: Needs a race window or specific setup
✓ lowers the bar for an attacker · ⚠ raises it
Proof of concept & exploit code
- reference https://github.com/langflow-ai/langflow/security/advisories/GHSA-qrpv-q767-xqq2
- github-search Search GitHub for public PoC repos
Test against your own equipment
curl -s https://vulnpedia.com/cve/CVE-2026-55255/poc.jsonMachine-readable PoC index for this CVE (for automation).Listed for defensive triage, patch verification, and authorized testing on systems you own. Machine-readable: /cve/CVE-2026-55255/poc.json
Weakness (CWE)
- CWE-639: : Authorization Bypass Through User-Controlled Key
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:L
Known Affected Software Configurations
| Vendor | Product | Version range |
|---|---|---|
| Langflow | Langflow | < 1.9.1 |
All CVSS metrics
- HIGH 8.4 v3.1 · CNA Primary
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:L - HIGH 8.4 v3.1 · NVD Secondary
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:L