Cyber Resilience

CVE-2026-33419

Minio ≤ 2026-03-17t21-25-16z

Published
24 March 2026
Modified
08 April 2026
Patch / advisory
CVSS Score v4 9.1
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0039 32th percentile
Risk Priority 45 floored blend · peak EPSS

Summary

CVE-2026-33419 is a critical-severity Observable Response Discrepancy (CWE-204) vulnerability in Minio Minio. Its CVSS base score is 9.1 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Brute Force (T1110); ranked at the 32th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to AC-7 (Unsuccessful Logon Attempts) and IA-6 (Authentication Feedback) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2026-33419 is a vulnerability in MinIO, a high-performance object storage system, specifically affecting the AIStor's STS (Security Token Service) AssumeRoleWithLDAPIdentity endpoint in versions prior to RELEASE.2026-03-17T21-25-16Z. It stems from two combined weaknesses: distinguishable error responses that enable username enumeration (CWE-204) and the absence of rate limiting on authentication attempts (CWE-307), collectively allowing LDAP credential brute-forcing. The vulnerability carries a CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N) and was published on 2026-03-24.

An unauthenticated network attacker can exploit this vulnerability by sending crafted requests to the endpoint to enumerate valid LDAP usernames based on differing error responses, followed by unlimited password guessing attempts against those accounts. If successful, the attacker obtains temporary AWS-style STS credentials, granting high-integrity access to the victim's S3 buckets and objects.

MinIO has patched this issue in release RELEASE.2026-03-17T21-25-16Z. Additional details on the vulnerability and mitigation are available in the security advisory at https://github.com/minio/minio/security/advisories/GHSA-jv87-32hw-hh99.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

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…

more

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.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1110 Brute Force Credential Access
Adversaries may use brute force techniques to gain access to accounts when passwords are unknown or when password hashes are obtained.
T1110.001 Password Guessing Credential Access
Adversaries with no prior knowledge of legitimate credentials within the system or environment may guess passwords to attempt access to accounts.
T1087 Account Discovery Discovery
Adversaries may attempt to get a listing of valid accounts, usernames, or email addresses on a system or within a compromised environment.
T1087.001 Local Account Discovery
Adversaries may attempt to get a listing of local system accounts.
T1087.002 Domain Account Discovery
Adversaries may attempt to get a listing of domain accounts.
T1087.003 Email Account Discovery
Adversaries may attempt to get a listing of email addresses and accounts.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2024-24747Same product: Minio Minio
CVE-2023-28434Same product: Minio Minio
CVE-2023-27589Same product: Minio Minio
CVE-2023-28432Same product: Minio Minio
CVE-2026-34204Same product: Minio Minio
CVE-2026-39414Same product: Minio Minio
CVE-2023-25812Same product: Minio Minio
CVE-2026-40344Same product: Minio Minio
CVE-2023-28433Same product: Minio Minio
CVE-2026-33322Same product: Minio Minio

Affected Assets

minio
minio
≤ 2026-03-17t21-25-16z

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 2 hardening rules · 1 OS baseline
Validate
Prove the fix (OWASP ASVS)
  • V13.4.5

Mitigating Controls (NIST 800-53 r5) AI

AC-7 directly enforces limits on consecutive failed logons, structurally blocking brute-force exploitation of the weakness.

Obscuring authentication feedback directly stops one common source of observable response discrepancies.

Error handling explicitly requires messages that avoid revealing exploitable internal information.

Information flow enforcement can block responses that would otherwise disclose internal state to unauthorized parties.

Boundary protection monitors and filters outbound responses that could leak internal state.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 full match
prevents

Secure SDLC practices directly prevent introduction of inconsistent response behavior that leaks internal state.

PR.AA-03 mostly match
prevents

Authentication enforcement directly includes lockout, throttling, and MFA policies that prevent brute-force attempts.

DE.CM-03 partial match
prevents

Behavioral monitoring of authentication activity can detect excessive failed attempts after they occur.

PR.PS-04 partial match
prevents

Generating auth logs enables later detection or forensics but does not itself restrict attempts.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

finds

Security testing can detect observable response discrepancies before deployment.

mitigates

Network security controls can enforce uniform responses and suppress observable discrepancies.

prevents

Secure SDLC practices include error-handling and response standardization to avoid information disclosure.

prevents

Application security requirements typically mandate consistent, non-revealing error messages.

prevents

Secure architecture principles discourage designs that leak internal state via differing responses.

prevents

Secure coding standards explicitly require uniform error handling to prevent information leakage.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

RHEL 7 (2 rules)
  • V-204427 The Red Hat Enterprise Linux operating system must be configured to lock accounts for a minimum of 15 minutes after three unsuccessful logon attempts within a 15-minute timeframe. prevents CWE-307
  • V-204428 The Red Hat Enterprise Linux operating system must lock the associated account after three unsuccessful root logon attempts are made within a 15-minute period. prevents CWE-307

References