CVE-2026-33419CWE-204CWE-307

MinIO: LDAP login brute-force via user enumeration and missing rate limit

Critical · published March 24, 2026

CVSS v4.0
9.1
EPSS
1%
Percentile
46.0
In the wild
Unconfirmed
What it is

MinIO is a high-performance object storage system. Prior to RELEASE.2026-03-17T21-25-16Z, MinIO AIStor's STS (Security Token Service) AssumeRoleWithLDAPIdentity endpoint is vulnerable to LDAP credential brute-forcing due to two combined weaknesses: (1) distinguishable error responses that enable username enumeration, and (2) absence of rate limiting on authentication attempts. An unauthenticated network attacker can enumerate valid LDAP usernames and then perform unlimited password guessing to obtain temporary AWS-style STS credentials, gaining access to the victim's S3 buckets and objects. This issue has been patched in RELEASE.2026-03-17T21-25-16Z.

The record
Technical detail
CVSS v4.0
9.1 · CRITICAL
Vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
EPSS
0.00562 · 46.0th percentile
Weaknesses
CWE-204 · Observable Response Discrepancy; CWE-307 · Improper Restriction of Excessive Authentication Attempts
Published
2026-03-24T19:05Z
EPSS history
Timeline
  • 24 MAR 19:05Z
    MinIO: LDAP login brute-force via user enumeration and missing rate limit
    cvelistv5