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Vulnerability record · CVE-2026-94368 · published 21 September 2026

CVE-2026-94368: Improper verification of cryptographic signature vulnerability

A flaw was found in the signature verification logic of noobaa-core, the core component of the NooBaa Multicloud Object Gateway. The issue occurs when the service processes S3 presigned URLs using Signature Version 4 (SigV4). Due to improper validation, the service fails to reject requests containing unsigned x-amz- headers, instead simply dropping them from the signature calculation. This allows an attacker who possesses a valid presigned PUT URL to add an unsigned x-amz-copy-source header, effectively converting a simple upload into a CopyObject operation. This can lead to unauthorized access and copying of any data the original signer is permitted to reach across the entire storage system.

7.1 CVSS 3.1 High EPSS 0.23% · top 87.6% CWE-347 · Improper verification of cryptographic signature Awaiting Analysis
7.1CVSS 3.1 base score
0.23%EPSS exploitation probability, 30 days
NoNot in CISA KEV
0Affected product versions listed by NVD
2References
22 Sep 2026Last modified by NVD

Description

A flaw was found in the signature verification logic of noobaa-core, the core component of the NooBaa Multicloud Object Gateway. The issue occurs when the service processes S3 presigned URLs using Signature Version 4 (SigV4). Due to improper validation, the service fails to reject requests containing unsigned x-amz- headers, instead simply dropping them from the signature calculation. This allows an attacker who possesses a valid presigned PUT URL to add an unsigned x-amz-copy-source header, effectively converting a simple upload into a CopyObject operation. This can lead to unauthorized access and copying of any data the original signer is permitted to reach across the entire storage system.

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N

References

LinkTags
https://access.redhat.com/security/cve/CVE-2026-94368
https://bugzilla.redhat.com/show_bug.cgi?id=2537364

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Source: NIST National Vulnerability Database (record CVE-2026-94368), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.