CVE-2026-34204

HighCVSS 7.1

Published: 31/03/2026(UTC)Updated: 24/07/2026(UTC)Translated: 25/07/2026(UTC)NVD NIST

Exploitation Probability (EPSS)

Low risk

0.12%

3th percentile - higher than 3% of all known CVEs

Summary

In MinIO, 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 PutObject request.

Risk Assessment

An attacker can bypass intended encryption or access protected data by manipulating encryption metadata.

Recommendation

Upgrade MinIO to version RELEASE.2026-03-26T21-24-40Z or later, which contains the fix.

Other vulnerabilities in MinIO

CVE-2026-39414Medium
MinIO from RELEASE.2018-08-18T03-49-57Z to before RELEASE.2025-12-20T04-58-37Z is vulnerable to memory exhaustion when processing CSV files containing lines longer than available memory. The CSV reader's nextSplit() function calls bufio.Reader.ReadBytes('\n') with no size limit, buffering the entire input in memory until a newline is found. A CSV file with no newline characters causes the entire contents to be read into a single allocation, leading to an OOM crash of the MinIO server process. This is exploitable by any authenticated user with s3:PutObject and s3:GetObject permissions. The attack is especially practical when combined with compression: a ~2 MB gzip-compressed CSV can decompress to gigabytes of data without newlines.

Original NVD description (English source)

MinIO is a high-performance object storage system. Prior to version RELEASE.2026-03-26T21-24-40Z, 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. This issue has been patched in version RELEASE.2026-03-26T21-24-40Z.