CVE-2026-86452 PUBLISHED

MISP Unauthenticated Mail Endpoints Allow Unbounded Storage Consumption and Request Flooding

Assigner: CIRCL
Reserved: 07.09.2026 Published: 07.09.2026 Updated: 07.09.2026

Affected versions of MISP permit unauthenticated or weakly constrained request paths to perform persistent work without adequate input bounds or rate limiting.

The users/forgot password-reset endpoint accepted an attacker-controlled email value without first imposing a reasonable length bound or validating its format. That value was then used to create an audit log entry and queue a password-reset job, causing the supplied value to be persisted more than once per request. The commit explicitly states that an unbounded unauthenticated request field was stored twice per call with no throttle.

The fix adds:

  • a maximum email input length of 1024 bytes;

  • email-format validation before persistent work;

  • a per-source pre-authentication request budget;

  • HTTP 429 responses when that budget is exceeded;

  • a 15-minute cooldown for API-access request emails;

  • POST-only handling and CSRF protection for the API-access request endpoint.

The new flood filter is specifically intended to limit persistent storage costs from anonymous requests such as password resets, registrations, and failed REST authentication attempts.

Version affected: ≤2.5.45

Metrics

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
CVSS Score: 8.7

Product Status

Vendor MISP
Product MISP
Versions Default: unaffected
  • affected from 0 to 2.5.45 (incl.)

Credits

  • Scottish Government - National Cyber Team finder
  • iglocska remediation developer
  • Claude Opus 5 (1M context) remediation developer

References

Problem Types

  • CWE-400 Uncontrolled Resource Consumption CWE
  • CWE-770 Allocation of Resources Without Limits or Throttling CWE

Impacts

  • CAPEC-125 Flooding