GHSA-3RH2-V3GR-35P9
Vulnerability from github – Published: 2026-03-27 22:26 – Updated: 2026-04-08 11:55Impact
What kind of vulnerability is it? Who is impacted?
A flaw in extractMetadataFromMime() allows any authenticated user with s3:PutObject permission to inject internal server-side encryption metadata into objects by sending crafted X-Minio-Replication-* headers on a normal PutObject request. The server unconditionally maps these headers to X-Minio-Internal-* encryption metadata without verifying that the request is a legitimate replication request. Objects written this way carry bogus encryption keys and become permanently unreadable through the S3 API.
Any authenticated user or service with s3:PutObject permission on any bucket can make objects permanently unreadable by injecting fake SSE encryption metadata. The attacker sends a standard PutObject request with X-Minio-Replication-Server-Side-Encryption-* headers but without the X-Minio-Source-Replication-Request header that marks legitimate replication traffic. The server maps these headers to internal encryption metadata (X-Minio-Internal-Server-Side-Encryption-Sealed-Key, etc.), causing all subsequent GetObject and HeadObject calls to treat the object as encrypted with keys that do not exist.
This is a targeted denial-of-service vulnerability. An attacker can selectively corrupt individual objects or entire buckets. The ReplicateObjectAction IAM permission is never checked because the request is a normal PutObject, not a replication request.
Affected component: cmd/handler-utils.go, function extractMetadataFromMime().
Affected Versions
All MinIO releases through the final release of the minio/minio open-source project.
The vulnerability was introduced in commit 468a9fae83e965ecefa1c1fdc2fc57b84ece95b0 ("Enable replication of SSE-C objects", PR #19107, 2024-03-28). The first affected release is RELEASE.2024-03-30T09-41-56Z.
Patches
Fixed in: MinIO AIStor RELEASE.2026-03-26T21-24-40Z
Binary Downloads
| Platform | Architecture | Download |
|---|---|---|
| Linux | amd64 | minio |
| Linux | arm64 | minio |
| macOS | arm64 | minio |
| macOS | amd64 | minio |
| Windows | amd64 | minio.exe |
FIPS Binaries
| Platform | Architecture | Download |
|---|---|---|
| Linux | amd64 | minio.fips |
| Linux | arm64 | minio.fips |
Package Downloads
| Format | Architecture | Download |
|---|---|---|
| DEB | amd64 | minio_20260326212440.0.0_amd64.deb |
| DEB | arm64 | minio_20260326212440.0.0_arm64.deb |
| RPM | amd64 | minio-20260326212440.0.0-1.x86_64.rpm |
| RPM | arm64 | minio-20260326212440.0.0-1.aarch64.rpm |
Container Images
# Standard
docker pull quay.io/minio/aistor/minio:RELEASE.2026-03-26T21-24-40Z
podman pull quay.io/minio/aistor/minio:RELEASE.2026-03-26T21-24-40Z
# FIPS
docker pull quay.io/minio/aistor/minio:RELEASE.2026-03-26T21-24-40Z.fips
podman pull quay.io/minio/aistor/minio:RELEASE.2026-03-26T21-24-40Z.fips
Homebrew (macOS)
brew install minio/aistor/minio
Workarounds
If upgrading is not immediately possible:
-
Restrict replication headers at a reverse proxy / load balancer. Drop or reject any request containing
X-Minio-Replication-Server-Side-Encryption-*headers that does not also carryX-Minio-Source-Replication-Request. This blocks the injection path without modifying the server. -
Audit IAM policies. Limit
s3:PutObjectgrants to trusted principals. While this reduces the attack surface, it does not eliminate the vulnerability since any authorized user can exploit it.
References
- Introducing commit:
468a9fae8(PR #19107) - MinIO AIStor
{
"affected": [
{
"package": {
"ecosystem": "Go",
"name": "github.com/minio/minio"
},
"ranges": [
{
"events": [
{
"introduced": "0.0.0-20240328174456-468a9fae83e9"
},
{
"last_affected": "0.0.0-20260212201848-7aac2a2c5b7c"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-34204"
],
"database_specific": {
"cwe_ids": [
"CWE-287"
],
"github_reviewed": true,
"github_reviewed_at": "2026-03-27T22:26:05Z",
"nvd_published_at": "2026-03-31T20:16:28Z",
"severity": "HIGH"
},
"details": "## Impact\n\n_What kind of vulnerability is it? Who is impacted?_\n\nA flaw in `extractMetadataFromMime()` allows any authenticated user with `s3:PutObject` permission to inject internal server-side encryption metadata into objects by sending crafted `X-Minio-Replication-*` headers on a normal PutObject request. The server unconditionally maps these headers to `X-Minio-Internal-*` encryption metadata without verifying that the request is a legitimate replication request. Objects written this way carry bogus encryption keys and become **permanently unreadable** through the S3 API.\n\nAny authenticated user or service with `s3:PutObject` permission on any bucket can make objects permanently unreadable by injecting fake SSE encryption metadata. The attacker sends a standard PutObject request with `X-Minio-Replication-Server-Side-Encryption-*` headers but **without** the `X-Minio-Source-Replication-Request` header that marks legitimate replication traffic. The server maps these headers to internal encryption metadata (`X-Minio-Internal-Server-Side-Encryption-Sealed-Key`, etc.), causing all subsequent GetObject and HeadObject calls to treat the object as encrypted with keys that do not exist.\n\nThis is a targeted denial-of-service vulnerability. An attacker can selectively corrupt individual objects or entire buckets. The `ReplicateObjectAction` IAM permission is never checked because the request is a normal PutObject, not a replication request.\n\n**Affected component:** `cmd/handler-utils.go`, function `extractMetadataFromMime()`.\n\n## Affected Versions\n\nAll MinIO releases through the final release of the minio/minio open-source project.\n\nThe vulnerability was introduced in commit `468a9fae83e965ecefa1c1fdc2fc57b84ece95b0` (\"Enable replication of SSE-C objects\", [PR #19107](https://github.com/minio/minio/pull/19107), 2024-03-28). The first affected release is `RELEASE.2024-03-30T09-41-56Z`.\n\n## Patches\n\n**Fixed in**: MinIO AIStor RELEASE.2026-03-26T21-24-40Z\n\n### Binary Downloads\n\n| Platform | Architecture | Download |\n| -------- | ------------ | -------- |\n| Linux | amd64 | [minio](https://dl.min.io/aistor/minio/release/linux-amd64/minio) |\n| Linux | arm64 | [minio](https://dl.min.io/aistor/minio/release/linux-arm64/minio) |\n| macOS | arm64 | [minio](https://dl.min.io/aistor/minio/release/darwin-arm64/minio) |\n| macOS | amd64 | [minio](https://dl.min.io/aistor/minio/release/darwin-amd64/minio) |\n| Windows | amd64 | [minio.exe](https://dl.min.io/aistor/minio/release/windows-amd64/minio.exe) |\n\n### FIPS Binaries\n\n| Platform | Architecture | Download |\n| -------- | ------------ | -------- |\n| Linux | amd64 | [minio.fips](https://dl.min.io/aistor/minio/release/linux-amd64/minio.fips) |\n| Linux | arm64 | [minio.fips](https://dl.min.io/aistor/minio/release/linux-arm64/minio.fips) |\n\n### Package Downloads\n\n| Format | Architecture | Download |\n| ------ | ------------ | -------- |\n| DEB | amd64 | [minio_20260326212440.0.0_amd64.deb](https://dl.min.io/aistor/minio/release/linux-amd64/minio_20260326212440.0.0_amd64.deb) |\n| DEB | arm64 | [minio_20260326212440.0.0_arm64.deb](https://dl.min.io/aistor/minio/release/linux-arm64/minio_20260326212440.0.0_arm64.deb) |\n| RPM | amd64 | [minio-20260326212440.0.0-1.x86_64.rpm](https://dl.min.io/aistor/minio/release/linux-amd64/minio-20260326212440.0.0-1.x86_64.rpm) |\n| RPM | arm64 | [minio-20260326212440.0.0-1.aarch64.rpm](https://dl.min.io/aistor/minio/release/linux-arm64/minio-20260326212440.0.0-1.aarch64.rpm) |\n\n### Container Images\n\n```bash\n# Standard\ndocker pull quay.io/minio/aistor/minio:RELEASE.2026-03-26T21-24-40Z\npodman pull quay.io/minio/aistor/minio:RELEASE.2026-03-26T21-24-40Z\n\n# FIPS\ndocker pull quay.io/minio/aistor/minio:RELEASE.2026-03-26T21-24-40Z.fips\npodman pull quay.io/minio/aistor/minio:RELEASE.2026-03-26T21-24-40Z.fips\n```\n\n### Homebrew (macOS)\n\n```bash\nbrew install minio/aistor/minio\n```\n\n## Workarounds\n\n[Users of the open-source `minio/minio` project should upgrade to MinIO AIStor `RELEASE.2026-03-26T21-24-40Z` or later.](https://docs.min.io/enterprise/aistor-object-store/upgrade-aistor-server/community-edition/)\n\nIf upgrading is not immediately possible:\n\n- **Restrict replication headers at a reverse proxy / load balancer.** Drop or reject any request containing `X-Minio-Replication-Server-Side-Encryption-*` headers that does not also carry `X-Minio-Source-Replication-Request`. This blocks the injection path without modifying the server.\n\n- **Audit IAM policies.** Limit `s3:PutObject` grants to trusted principals. While this reduces the attack surface, it does not eliminate the vulnerability since any authorized user can exploit it.\n\n## References\n\n- Introducing commit: [`468a9fae8`](https://github.com/minio/minio/commit/468a9fae83e965ecefa1c1fdc2fc57b84ece95b0) ([PR #19107](https://github.com/minio/minio/pull/19107))\n- [MinIO AIStor](https://min.io/aistor)",
"id": "GHSA-3rh2-v3gr-35p9",
"modified": "2026-04-08T11:55:44Z",
"published": "2026-03-27T22:26:05Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/minio/minio/security/advisories/GHSA-3rh2-v3gr-35p9"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-34204"
},
{
"type": "WEB",
"url": "https://docs.min.io/enterprise/aistor-object-store/upgrade-aistor-server/community-edition"
},
{
"type": "PACKAGE",
"url": "https://github.com/minio/minio"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N",
"type": "CVSS_V4"
}
],
"summary": "MinIO is Vulnerable to SSE Metadata Injection via Replication Headers"
}
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.