CVE on SILO

CVE-2026-32285: The jsonparser Advisory That Required No Patch

Wed, 15 Apr 2026 00:00:00 +0000

Status: Closed without a code change
GitHub issue: pgsty/minio#26

Security maintenance is not always a sequence of “find a vulnerability, then ship a patch.” The initial assessment of CVE-2026-32285 was that the repository might still carry a vulnerable jsonparser; replacing the dependency or maintaining another fork was even considered. Checking the resolved module version and actual reachability changed the conclusion: the tree already used v1.1.2, which contained the fix, and govulncheck found no reachable vulnerable symbol.

CVE-2026-33322: OIDC JWT Algorithm Confusion

Wed, 15 Apr 2026 00:00:00 +0000

Status: Released
First containing release: RELEASE.2026-04-17T00-00-00Z
Affected entry points: AssumeRoleWithWebIdentity, AssumeRoleWithClientGrants
GitHub issue: pgsty/minio#22

The old implementation placed the OIDC client secret in the JWT verifier keyring while also accepting HMAC signing methods. An attacker who knew that client secret could therefore mint an HS-signed token and exchange it through STS for temporary credentials. The final fix restored asymmetric, JWKS-only verification. It deliberately broke HS256/384/512 compatibility instead of keeping an option that would reintroduce ambiguous trust semantics.

CVE-2026-33419: LDAP STS Enumeration and the Throttling Chain

Wed, 15 Apr 2026 00:00:00 +0000

Status: Released, followed by two rounds of corrections
First containing release: RELEASE.2026-04-17T00-00-00Z
Complete correction: RELEASE.2026-06-18T00-00-00Z
GitHub issue: pgsty/minio#23

The core vulnerability was straightforward: LDAP STS returned different results for “user does not exist” and “password is wrong,” creating a username oracle. The first fix unified the external authentication failure and added limits by source IP and username. Continued review then showed that success refunds, spoofable source headers, reservation accounting, and the shared username bucket could turn the security control itself into a new attack surface.

CVE-2026-34204: Replication Metadata Injection

Wed, 15 Apr 2026 00:00:00 +0000

Status: Released
First containing release: RELEASE.2026-04-17T00-00-00Z
GitHub issue: pgsty/minio#24

Ordinary PUT and COPY requests could smuggle X-Minio-Replication-* headers into internal X-Minio-Internal-* SSE metadata, creating objects whose replication state did not match the authorized path and could even make them unreadable. The final fix stopped accepting replication-only metadata by default, restored it only in a trusted flow authorized for ReplicateObjectAction, and sanitized CopyObject before any header consumer ran.

Threat model

An attacker needed only ordinary object-write permission, not internode credentials. The input came entirely from client-controlled X-Minio-Replication-* headers, but metadata extraction converted it into internal replication or SSE state.

CVE-2026-39414: Oversized S3 Select Records and a SIMD Bypass

Wed, 15 Apr 2026 00:00:00 +0000

Status: Released; the second-round fix was completed in June
Initial fix release: RELEASE.2026-04-17T00-00-00Z
Complete fix release: RELEASE.2026-06-18T00-00-00Z
GitHub issue: pgsty/minio#25

The first fix in April reused the existing 1 MiB maxCharsPerRecord limit for both CSV and ordinary JSON Lines. This prevented unbounded buffering while waiting for a delimiter and returned the explicit OverMaxRecordSize error to clients. A June review then found that CPUs with SIMD support took a different simdjson fast path that bypassed the limit completely.

CVE-2026-40344: Snowball Auto-Extract Authentication Bypass

Thu, 16 Apr 2026 00:00:00 +0000

Status: Released
First containing release: RELEASE.2026-04-17T00-00-00Z
GitHub advisory: GHSA-9c4q-hq6p-c237

Snowball’s PutObjectExtractHandler omitted the streaming unsigned-trailer authentication case. A tar stream with a forged signature could enter untar() before authentication completed, and one request could fan out into many object writes. The final fix initialized the correct reader, handled the decoded length, and completed SigV4 verification before any tar byte reached the extractor.

Why the identifier changed

The official CVE had not been assigned when the fix was written, so the commit subject used the temporary identifier fake CVE-2026-40028. The final identifier is CVE-2026-40344. The historical commit was not rewritten; the advisory and this article use the official number.

CVE-2026-41145: Unsigned-Trailer Query Authentication Bypass

Thu, 16 Apr 2026 00:00:00 +0000

Status: Released
First containing release: RELEASE.2026-04-17T00-00-00Z
GitHub advisory: GHSA-hv4r-mvr4-25vw

Query-string SigV4 credentials could enter a STREAMING-UNSIGNED-PAYLOAD-TRAILER data flow, while the old code verified the signature only when an Authorization header was present. A request carrying a valid access-key identifier could therefore complete a write without a correct signature.

The final fix moved presigned rejection and SigV4 verification into newUnsignedV4ChunkedReader(), making every caller consuming that stream share one authentication boundary.

Identifier note

The official CVE had not been assigned when the patch was written, so its commit subject used fake CVE-2026-40027. The final identifier is CVE-2026-41145. The historical commit remains unchanged; public material uses the official identifier.

CVE-2026-42600: ReadMultiple Storage-REST Path Traversal

Fri, 12 Jun 2026 00:00:00 +0000

Status: Released
First containing release: RELEASE.2026-06-18T00-00-00Z
GitHub advisory: GHSA-xh8f-g2qw-gcm7
Affected scope: Distributed erasure only; cluster-root / internode JWT required

The msgpack body of /rmpl carried Bucket, Prefix, and Files. The old code joined those values into filesystem paths without a containment check. The initial fix implemented full preflight validation. Continued call-chain review then found that this API had had no production caller since 2024. The final solution changed from “retain and harden” to removing the route, handler, client, interface, and generated code.