CVE-2026-54330

Aliases:DEBIAN-CVE-2026-54330UBUNTU-CVE-2026-54330
Advisory lineage Upstream: 0 Downstream: 1
Downstream
MGASA-2026-0389
Awaiting Analysis
Published: 27 Aug 2026, 20:59
Last modified:01 Sept 2026, 03:56

Vulnerability Summary

Overall Risk (default)
medium
32/100
CVSS Score
8.1 HIGH
v3.1 (cve.org)
EPSS Score
0.18% LOW
0% probability 0.00%
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

27 Aug 2026, 20:59
Published
Vulnerability first disclosed
01 Sept 2026, 03:56
Last Modified
Vulnerability information updated

Description

Ceph is an open-source distributed storage platform providing object, block, and file storage. In versions prior to 20.2.4 and 19.2.6, the Ceph Object Gateway (RGW) SigV4 handler does not reject requests that carry x-amz-* headers absent from the signed header set, allowing anyone holding a presigned URL to attach arbitrary unsigned x-amz-* headers that RGW will honor. AWS S3 requires every x-amz-* header on a SigV4 request to be signed and rejects requests bearing additional unsigned headers, but RGW validates only the headers listed in X-Amz-SignedHeaders and ignores any extra ones, so they take effect without being covered by the signature. By adding such headers to a presigned PUT URL, an attacker can grant themselves more capabilities than the URL's signer intended and escalate their privileges. This issue is fixed in versions 20.2.4 and 19.2.6.

CVSS Metrics

  • v3.1•HIGH•Score: 8.1CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

EPSS Trends

Current EPSS score: 0.18%• Percentile: 8%

Techniques & Countermeasures

  • CWE-347•Improper Verification of Cryptographic Signature

    The product does not verify, or incorrectly verifies, the cryptographic signature for data.

Affected Systems

  • ceph•ceph

    ≥ 19.0.0, < 19.2.6 | ≥ 20.0.0, < 20.2.4

  • debian•ceph

    all | all | all | all | < 20.2.4+ds-1

  • ubuntu•ceph

    all | all | all | all

References (7)