Langflow flaws being used in attacks

CISA lists 5 flaws in Langflow products as being used in attacks, most recently on 21 Jul 2026. 1 has been used in ransomware.

What to do

1. Update every Langflow product you use.Install the updates Langflow offers, on every device, and restart when asked. Each flaw below has a fix or clear advice; that’s one of CISA’s conditions for listing it.
2. If someone looks after IT for you, send them this page.Many of these are in equipment you don’t see: routers, firewalls, servers, the office network. Ask them to confirm each one is fixed, or that you don’t use the product.
3. Check anything else in the lookup.Search any app, company or CVE. Not being on CISA’s list doesn’t mean safe: keep updating either way.

Every flaw, newest first

1. Being used in attacksAdded by CISA on 21 Jul 2026
   Langflow
   CVE-2026-0770Langflow Inclusion of Functionality from Untrusted Control Sphere Vulnerability
   Langflow contains an inclusion of functionality from untrusted control sphere vulnerability that allows remote attackers to execute arbitrary code on affected installations.
   CISA’s required actionApply 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). Read all

   Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
   CVE recordNVD
2. Being used in attacksAdded by CISA on 7 Jul 2026
   Langflow
   CVE-2026-55255Langflow Authorization Bypass Through User-Controlled Key Vulnerability
   Langflow contains an authorization bypass through user-controlled key vulnerability which allows an authenticated attacker to execute any flow belonging to another user by specifying the victim's flow ID in the request.
   CISA’s required actionApply 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). Read all

   Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
   CVE recordNVD
3. Being used in attacksAdded by CISA on 21 May 2026
   Langflow
   CVE-2025-34291Langflow Origin Validation Error Vulnerability
   Langflow contains an origin validation error vulnerability in which an overly permissive CORS configuration combined with a refresh token cookie configured as SameSite=None allows a malicious webpage to perform cross-origin requests that include credentials and successfully call the refresh endpoint. This could allow the attacker to execute arbitrary code and achieve full system compromise via obtained tokens that permit access to authenticated endpoints.
   CISA’s required actionApply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
   CVE recordNVD
4. Being used in attacksAdded by CISA on 25 Mar 2026
   Langflow
   CVE-2026-33017Langflow Code Injection Vulnerability
   Langflow contains a code injection vulnerability that could allow building public flows without requiring authentication.
   CISA’s required actionApply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
   CVE recordNVD
5. Being used in attacksUsed in ransomwareAdded by CISA on 5 May 2025
   Langflow
   CVE-2025-3248Langflow Missing Authentication Vulnerability
   Langflow contains a missing authentication vulnerability in the /api/v1/validate/code endpoint that allows a remote, unauthenticated attacker to execute arbitrary code via crafted HTTP requests.
   CISA’s required actionApply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
   CVE recordNVD

From CISA’s Known Exploited Vulnerabilities catalog, updated 21 Oct 2026 (version 2026.10.21). CISA’s required actions are written for US government agencies. Langflow on CISA’s site.