CVE-2026-90535: Missing Authorization in FlowiseAI Flowise
Flowise versions before 3.1.4 contain an unauthenticated denial of service vulnerability in the /api/v1/text-to-speech/abort endpoint that accepts user-supplied chatflowId and chatId without ownership verification. Attackers can terminate active chatflow predictions for any user by submitting requests with known chatflow and chat identifiers, causing targeted service disruption.
AI Analysis
Technical Summary
CVE-2026-90535 describes a missing authorization vulnerability in Flowise prior to version 3.1.4. The /api/v1/text-to-speech/abort endpoint does not verify that the requester owns the chatflowId and chatId provided, enabling unauthenticated attackers to abort active chatflow predictions belonging to other users. This results in a denial of service condition affecting targeted users.
Potential Impact
An attacker can cause denial of service by terminating active chatflow predictions of any user without authentication or ownership verification. This disrupts the availability of the service for targeted users but does not indicate data confidentiality or integrity impact.
Mitigation Recommendations
Upgrade Flowise to version 3.1.4 or later, where this authorization issue is fixed. No other mitigation guidance is provided. Patch status is confirmed by the affectedVersions field indicating versions before 3.1.4 are vulnerable.
CVE-2026-90535: Missing Authorization in FlowiseAI Flowise
Description
Flowise versions before 3.1.4 contain an unauthenticated denial of service vulnerability in the /api/v1/text-to-speech/abort endpoint that accepts user-supplied chatflowId and chatId without ownership verification. Attackers can terminate active chatflow predictions for any user by submitting requests with known chatflow and chat identifiers, causing targeted service disruption.
CVSS v4.0
Score 6.3medium
Affected software
FlowiseAI
Flowise
pkg:github/flowiseai/FlowiseRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-90535 describes a missing authorization vulnerability in Flowise prior to version 3.1.4. The /api/v1/text-to-speech/abort endpoint does not verify that the requester owns the chatflowId and chatId provided, enabling unauthenticated attackers to abort active chatflow predictions belonging to other users. This results in a denial of service condition affecting targeted users.
Potential Impact
An attacker can cause denial of service by terminating active chatflow predictions of any user without authentication or ownership verification. This disrupts the availability of the service for targeted users but does not indicate data confidentiality or integrity impact.
Mitigation Recommendations
Upgrade Flowise to version 3.1.4 or later, where this authorization issue is fixed. No other mitigation guidance is provided. Patch status is confirmed by the affectedVersions field indicating versions before 3.1.4 are vulnerable.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulnCheck
- Date Reserved
- 2026-09-12T11:12:50.791Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6aa5465055bf5e2cf54629cc
Added to database: 09/12/2026, 12:32:16 UTC
Last enriched: 09/12/2026, 13:06:02 UTC
Last updated: 09/13/2026, 00:47:19 UTC
Views: 9
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.