CVE-2026-54330

8.1 HIGH 0.4% exploit odds Fix listed Crypto

What it is

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.

At a glance

Exploitability: Can be exploited over the network with a low-privilege account. High risk of data exposure, data tampering.
Exploit odds: 0.4% chance of exploitation in the next 30 days (EPSS).
Fix: A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

2026-08-28 00:18 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-09-08 21:11 UTC Last updatedMost recent change to the record

Why it ranks here

Exploited in the wild: no, CISA does not list it.
Exploit odds: 0.4% in the next 30 days (EPSS).
Severity: 8.1 HIGH (CVSS).
Fix: a patch or advisory is linked.

Details

Published: 2026-08-28 00:18 UTC
Last modified: 2026-09-08 21:11 UTC
Exploit probability: 0.4% · EPSS, next 30 days
Weakness: CWE-347
Record status: Awaiting Analysis

Attack profile CVSS 3.1 · 8.1

Attack vector: Network
Complexity: Low
Privileges needed: Low
User interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: None

Raw vector

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

Is it in your code?

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Read https://cve-list.com/agent/cve/CVE-2026-54330.md and follow it. Check whether this project is affected by CVE-2026-54330. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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Fix and advisories

References

NVD record · CVE.org record