{"id":"CVE-2026-54330","title":"Ceph is an open-source distributed storage platform providing object, block, and file storage","summary":"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…","severity":"high","cvss":8.1,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N","cwe":["CWE-347"],"published":"2026-08-28","updated":"2026-09-08","sourceUpdated":"2026-09-08T21:11:56.250","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-54330","references":[{"url":"https://github.com/ceph/ceph/commit/5837aa8e60471128dbb672b0ff6f1b1feebe08a7","label":"security-advisories@github.com"},{"url":"https://github.com/ceph/ceph/commit/5978c866d4a0812fbb024745c4f1e79aaecd6c6a","label":"security-advisories@github.com"},{"url":"https://github.com/ceph/ceph/security/advisories/GHSA-rmjq-ffrm-j6vj","label":"security-advisories@github.com"}],"tags":["nvd"],"epss":0.00367,"epssPercentile":0.27801,"ingestedAt":"2026-09-08T22:12:30.941Z","slug":"CVE-2026-54330","body":"## Overview\n\nCeph 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":45,"depthScoreParts":{"impact":44.6,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}