Executive brief
MISP is an open-source threat intelligence and incident response platform. The password reset and API access request endpoints accepted arbitrarily large email addresses without validation or rate limiting, allowing attackers to exhaust server storage and computational resources by sending many requests with oversized payloads. This could degrade or disable the service for legitimate users.
Technical details
The vulnerability is a denial-of-service (DoS) condition caused by inadequate input validation and rate limiting on unauthenticated endpoints. The /users/forgot and request_API endpoints accepted unbounded, unauthenticated email parameters that were persisted twice per request (in audit logs and job queues) without validation or throttling. An attacker could repeatedly submit requests with extremely long email strings or invalid formats to consume storage and processing resources. The fix introduces a 1024-byte maximum email length, format validation, per-source request budgets with HTTP 429 rate-limiting responses, and a 15-minute cooldown for API-access requests. The vulnerability is unauthenticated and network-reachable, making it trivially exploitable.
Affected products
- MISP MISP ≤2.5.45
Timeline
- 2026-09-07: disclosed: CVE-2026-86452 published
- 2026-09-01: patched: Fix committed