GO-2026-4779Published

MinIO: JWT Algorithm Confusion in OIDC Authentication

Collected exploitation and prediction evidence

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

cve-program · CVE-2026-33322

Published

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.

Source published: 24 Mar 2026 19:05:04 UTC
Source modified: 25 Mar 2026 14:28:14 UTC
Observed here: 23 Oct 2026 15:48:27 UTC
Source terms: CVE Program Terms of Use

Original source record · Cite this exact observation · Complete original publisher JSON

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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

euvd · EUVD-2026-20095

Published

EUVD source date text has no stated timezone and is retained without inventing a UTC instant. Related bulletin membership is not an alias, common cause or applicability claim. A missing vector with a zero score is treated as unrated. Complete vendor/product and underlying source evidence remains in the original JSON.

Original publisher date fields

datePublished: Mar 24, 2026, 7:05:04 PM

dateUpdated: Mar 25, 2026, 2:28:14 PM

Source published: Mar 24, 2026, 7:05:04 PM (timezone not stated)
Source modified: Mar 25, 2026, 2:28:14 PM (timezone not stated)
Observed here: 11 Nov 2026 08:36:31 UTC
Source terms: ENISA EUVD · source terms and attribution apply

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EUVD 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

nvd · CVE-2026-33322

Published

NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON.

Source analysis status: Analyzed

Weakness classifications: CWE-287

Original publisher date fields

published: 2026-03-24T20:16:27.857

lastModified: 2026-06-17T10:37:19.350

1 source CPE criteria · context only

cpe:2.3:a:minio:minio:*:*:*:*:*:*:*:*

The original JSON retains the logical configuration operators, exclusions and version bounds.

Source published: 24 Mar 2026 20:16:27 UTC
Source modified: 17 Jun 2026 10:37:19 UTC
Observed here: 25 Oct 2026 08:17:18 UTC
Source terms: NIST NVD usage terms; underlying source attribution retained

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: nvd · NIST NVD usage terms; underlying source attribution retained. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 4.0 · [email protected] · Secondary · 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/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

CVSS 3.1 · [email protected] · Primary · 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

osv · GHSA-5cx5-wh4m-82fh

Published

### Impact _What kind of vulnerability is it? Who is impacted?_ 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`. An attacker with knowledge of the OIDC `ClientSecret` can: - Impersonate any user identity - Obtain S3 credentials with any IAM policy, including `consoleAdmin` - Access, modify, or delete any data in the MinIO deployment The attack is deterministic (100% success rate, no race conditions). #### Attack Prerequisites The attacker must know the OIDC `ClientSecret`. While this is a shared credential (not a private key), it is more accessible than commonly assumed: - CVE-2023-28432 previously leaked environment variables including `MINIO_IDENTITY_OPENID_CLIENT_SECRET` - Client secrets are often present in frontend OAuth configurations, mobile app bundles, CI/CD pipelines, and shared configuration files - In many organizations, the client secret is accessible to operators and engineers who should not be able to forge arbitrary identities #### Affected Versions All MinIO releases from `RELEASE.2022-11-08T05-27-07Z` through the final release of the `minio/minio` open-source project. ### Patches **Fixed in:** MinIO AIStor `RELEASE.2026-03-17T21-25-16Z` ## Downloads ### Binary Downloads | Platform | Architecture | Download | | -------- | ------------ | --------------------------------------------------------------------------- | | Linux | amd64 | [minio](https://dl.min.io/aistor/minio/release/linux-amd64/minio) | | Linux | arm64 | [minio](https://dl.min.io/aistor/minio/release/linux-arm64/minio) | | macOS | arm64 | [minio](https://dl.min.io/aistor/minio/release/darwin-arm64/minio) | | macOS | amd64 | [minio](https://dl.min.io/aistor/minio/release/darwin-amd64/minio) | | Windows | amd64 | [minio.exe](https://dl.min.io/aistor/minio/release/windows-amd64/minio.exe) | ### FIPS Binaries | Platform | Architecture | Download | | -------- | ------------ | --------------------------------------------------------------------------- | | Linux | amd64 | [minio.fips](https://dl.min.io/aistor/minio/release/linux-amd64/minio.fips) | | Linux | arm64 | [minio.fips](https://dl.min.io/aistor/minio/release/linux-arm64/minio.fips) | ### Package Downloads | Format | Architecture | Download | | ------ | ------------ | ----------------------------------------------------------------------------------------------------------------------------------- | | DEB | amd64 | [minio_20260317212516.0.0_amd64.deb](https://dl.min.io/aistor/minio/release/linux-amd64/minio_20260317212516.0.0_amd64.deb) | | DEB | arm64 | [minio_20260317212516.0.0_arm64.deb](https://dl.min.io/aistor/minio/release/linux-arm64/minio_20260317212516.0.0_arm64.deb) | | RPM | amd64 | [minio-20260317212516.0.0-1.x86_64.rpm](https://dl.min.io/aistor/minio/release/linux-amd64/minio-20260317212516.0.0-1.x86_64.rpm) | | RPM | arm64 | [minio-20260317212516.0.0-1.aarch64.rpm](https://dl.min.io/aistor/minio/release/linux-arm64/minio-20260317212516.0.0-1.aarch64.rpm) | ### Container Images ```bash # Standard docker pull quay.io/minio/aistor/minio:RELEASE.2026-03-17T21-25-16Z podman pull quay.io/minio/aistor/minio:RELEASE.2026-03-17T21-25-16Z # FIPS docker pull quay.io/minio/aistor/minio:RELEASE.2026-03-17T21-25-16Z.fips podman pull quay.io/minio/aistor/minio:RELEASE.2026-03-17T21-25-16Z.fips ``` ### Homebrew (macOS) ```bash brew install minio/aistor/minio ``` ### Workarounds - [Users of the open-source `minio/minio` project should upgrade to MinIO AIStor `RELEASE.2026-03-17T21-25-16Z` or later.](https://docs.min.io/enterprise/aistor-object-store/upgrade-aistor-server/community-edition/) - As a workaround, ensure that the OIDC `ClientSecret` is treated as a highly sensitive credential and is not exposed to untrusted parties.

Source published: 19 Mar 2026 17:56:37 UTC
Source modified: 8 Oct 2026 08:11:02 UTC
Observed here: 24 Oct 2026 13:19:41 UTC
Source terms: GitHub Advisory Database · CC-BY-4.0

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V4 · 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

Publisher rating · CRITICAL

osv · GO-2026-4779

Published

MinIO has JWT Algorithm Confusion in OIDC Authentication in github.com/minio/minio

Source published: 23 Mar 2026 18:16:14 UTC
Source modified: 8 Oct 2026 08:11:02 UTC
Observed here: 24 Oct 2026 13:19:41 UTC
Source terms: OSV · upstream source license applies

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · OSV · upstream source license applies. Source text is retained; field grouping and change labels are provided by ChangeIntel.