---
title: "CVE-2026-33322: MinIO has JWT Algorithm Confusion in OIDC Authentication"
url: https://erroneo.us/security/cve/CVE-2026-33322/
description: "CVE-2026-33322 (github.com/minio/minio (Go)): MinIO is a high-performance object storage system. From RELEASE.2022-11-08T05-27-07Z to before…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-03-24
date_modified: 2026-03-27
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-33322"
kev: false
cvss: 9.2
epss: 0.00629
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-33322: MinIO has JWT Algorithm Confusion in OIDC Authentication

**Signal:** Critical and remotely reachable. No known exploitation yet, but it is network-reachable without credentials. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
- EPSS 0.6% , percentile 49: FIRST’s model estimates a 0.6% chance of exploitation activity in the next 30 days, higher than 49% of all scored CVEs (low). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Only applies if your dependency tree includes github.com/minio/minio (Go) <= 0.0.0-20260212201848-7aac2a2c5b7c, no fixed version listed . Check your lockfile, including transitive dependencies.

## What it is

MinIO is a high-performance object storage system. From RELEASE.2022-11-08T05-27-07Z to before RELEASE.2026-03-17T21-25-16Z, a JWT algorithm confusion vulnerability in MinIO's OpenID Connect authentication allows an attacker who knows the OIDC ClientSecret to forge arbitrary identity tokens and obtain S3 credentials with any policy, including consoleAdmin. This issue has been patched in RELEASE.2026-03-17T21-25-16Z.

## Affected packages

- Go `github.com/minio/minio` <= 0.0.0-20260212201848-7aac2a2c5b7c → fixed: none listed

## Affected products (CVE record)

- minio minio: >= RELEASE.2022-11-08T05-27-07Z, < RELEASE.2026-03-17T21-25-16Z

## Severity

- GitHub_M CVSS 4.0: 9.2 `CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`
- GitHub CVSS 4.0: 9.2 `CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none , automatable no , technical impact total .
- FIRST EPSS (model of 2026-10-21): 0.63% probability of exploitation activity in the next 30 days; percentile 49.

## Sources

- [GitHub Advisory GHSA-5cx5-wh4m-82fh](https://github.com/advisories/GHSA-5cx5-wh4m-82fh)
- [CVE.org record CVE-2026-33322](https://www.cve.org/CVERecord?id=CVE-2026-33322)
- [NVD entry CVE-2026-33322](https://nvd.nist.gov/vuln/detail/CVE-2026-33322)
- [github.com](https://github.com/minio/minio/security/advisories/GHSA-5cx5-wh4m-82fh)

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Source page: https://erroneo.us/security/cve/CVE-2026-33322/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt