# CVE-2026-33419: MinIO: LDAP login brute-force via user enumeration and missing rate limit

> Attackers can brute-force LDAP credentials via the STS endpoint to gain unauthorized access to S3 buckets and objects.

- **Severity:** Critical 9.1 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 24 Mar 2026
- **Updated:** 25 Mar 2026
- **Also known as:** GHSA-jv87-32hw-hh99, GO-2026-4803, MINI-332m-jx4w-xqgc, MINI-q8w4-wxgw-6h7p

## What is CVE-2026-33419?

CVE-2026-33419 is a critical authentication bypass vulnerability in minio, published on 24 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

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.

Weakness: CWE-307 (Improper Restriction of Excessive Authentication Attempts), CWE-204 (Observable Response Discrepancy)

## Which versions are affected by CVE-2026-33419?

3 open source packages ship an affected version, including github.com/minio/minio. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/minio/minio` | Go | All versions | None |
| `github.com/minio/minio` | Go | All versions to 0.0.0-20260212201848-7aac2a2c5b7c | None |
| `github.com/minio/minio` | Go | All versions to 0.0.0-20260212201848-7aac2a2c5b7c | None |

Products: Minio Minio.

## How do I fix CVE-2026-33419?

Upgrade to a fixed version.

## Is CVE-2026-33419 being exploited?

There is no known exploitation of CVE-2026-33419 in the wild and no public exploit code.

## Other vulnerabilities in minio

- [CVE-2023-28434](https://insights.sbomify.com/CVE-2023-28434/): MinIO Security Feature Bypass (high 8.8, exploited in the wild)
- [CVE-2023-28432](https://insights.sbomify.com/CVE-2023-28432/): MinIO Information Disclosure (high 7.5, exploited in the wild)
- [CVE-2020-11012](https://insights.sbomify.com/CVE-2020-11012/): Authentication bypass MinIO Admin API (critical 9.3)
- [CVE-2026-33322](https://insights.sbomify.com/CVE-2026-33322/): MinIO: JWT Algorithm Confusion in OIDC Authentication (critical 9.2)
- [CVE-2026-40344](https://insights.sbomify.com/CVE-2026-40344/): MinIO has an Unauthenticated Object Write via Missing Signature Verification in Unsigned-Trailer Uploads (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-33419 and fix it if it is affected.

What it is: CVE-2026-33419 is a critical authentication bypass vulnerability in minio, published on 24 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-33419 in the wild and no public exploit code.

Affected packages and fixed versions:
- github.com/minio/minio (Go): affected all versions; no fix listed
- github.com/minio/minio (Go): affected all versions up to 0.0.0-20260212201848-7aac2a2c5b7c; no fix listed
- github.com/minio/minio (Go): affected all versions up to 0.0.0-20260212201848-7aac2a2c5b7c; no fix listed

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-33419/ (Markdown: https://insights.sbomify.com/CVE-2026-33419/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-33419
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-33419
- OSV: https://osv.dev/vulnerability/CVE-2026-33419

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-33419/
Summaries are generated and may contain mistakes; the official description above is the record.