NVD / CVE Program· CNA GitHub_M

CVE-2026-54330: Ceph RGW SigV4 handler accepts unsigned x-amz-* headers on presigned requests, allowing privilege escalation

HighCVSS 8.1 · v3.1—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 32/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 0.36% (FIRST EPSS).
Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
Fixed version: azl3 ceph 18.2.2-12 on Azure Linux 3.0 18.2.2-13.

Low priority for now. Upgrade to azl3 ceph 18.2.2-12 on Azure Linux 3.0 18.2.2-13 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

Weak crypto

Published: Aug 27, 2026
Updated: Sep 8, 2026
EPSS: 0.3% · 30th percentile
CWE: CWE-347

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 32 / 40 · 8.1 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.3%

CISA SSVC decision

Exploitation: none
Automatable: no
Technical impact: total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: —
CNA · GitHub_M: 8.1; NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

Not in KEV: no record of exploitation in the wild
No public exploit code on record
A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Is your version affected? Check it

Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

ceph ceph
- >= 19.0.0, < 19.2.6, >= 20.0.0, < 20.2.4affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Ecosystem	Package	Affected range	Fix
Debian:12	ceph	from 0	—
Debian:14	ceph	before 20.2.4+ds-1	20.2.4+ds-1
Red Hat:ceph_storage:8.1::el9	ceph	before 2:19.2.1-423.el9cp	2:19.2.1-423.el9cp
Red Hat:ceph_storage:8.1::el9	ceph-base	before 2:19.2.1-423.el9cp	2:19.2.1-423.el9cp
Red Hat:ceph_storage:8.1::el9	ceph-base-debuginfo	before 2:19.2.1-423.el9cp	2:19.2.1-423.el9cp
Red Hat:ceph_storage:8.1::el9	ceph-common	before 2:19.2.1-423.el9cp	2:19.2.1-423.el9cp
Red Hat:ceph_storage:8.1::el9	ceph-common-debuginfo	before 2:19.2.1-423.el9cp	2:19.2.1-423.el9cp
Red Hat:ceph_storage:8.1::el9	ceph-debuginfo	before 2:19.2.1-423.el9cp	2:19.2.1-423.el9cp
Red Hat:ceph_storage:8.1::el9	ceph-debugsource	before 2:19.2.1-423.el9cp	2:19.2.1-423.el9cp
Red Hat:ceph_storage:8.1::el9	ceph-exporter-debuginfo	before 2:19.2.1-423.el9cp	2:19.2.1-423.el9cp
Red Hat:ceph_storage:8.1::el9	ceph-fuse	before 2:19.2.1-423.el9cp	2:19.2.1-423.el9cp
Red Hat:ceph_storage:8.1::el9	ceph-fuse-debuginfo	before 2:19.2.1-423.el9cp	2:19.2.1-423.el9cp
Red Hat:ceph_storage:8.1::el9	ceph-immutable-object-cache	before 2:19.2.1-423.el9cp	2:19.2.1-423.el9cp
Red Hat:ceph_storage:8.1::el9	ceph-immutable-object-cache-debuginfo	before 2:19.2.1-423.el9cp	2:19.2.1-423.el9cp
Red Hat:ceph_storage:8.1::el9	ceph-mds-debuginfo	before 2:19.2.1-423.el9cp	2:19.2.1-423.el9cp
Red Hat:ceph_storage:8.1::el9	ceph-mgr-debuginfo	before 2:19.2.1-423.el9cp	2:19.2.1-423.el9cp
Red Hat:ceph_storage:8.1::el9	ceph-mib	before 2:19.2.1-423.el9cp	2:19.2.1-423.el9cp
Red Hat:ceph_storage:8.1::el9	ceph-mon-client-nvmeof-debuginfo	before 2:19.2.1-423.el9cp	2:19.2.1-423.el9cp
Red Hat:ceph_storage:8.1::el9	ceph-mon-debuginfo	before 2:19.2.1-423.el9cp	2:19.2.1-423.el9cp
Red Hat:ceph_storage:8.1::el9	ceph-osd-debuginfo	before 2:19.2.1-423.el9cp	2:19.2.1-423.el9cp
Red Hat:ceph_storage:8.1::el9	ceph-radosgw-debuginfo	before 2:19.2.1-423.el9cp	2:19.2.1-423.el9cp
Red Hat:ceph_storage:8.1::el9	ceph-resource-agents	before 2:19.2.1-423.el9cp	2:19.2.1-423.el9cp
Red Hat:ceph_storage:8.1::el9	ceph-selinux	before 2:19.2.1-423.el9cp	2:19.2.1-423.el9cp
Red Hat:ceph_storage:8.1::el9	ceph-test-debuginfo	before 2:19.2.1-423.el9cp	2:19.2.1-423.el9cp

+37

Same product

ceph: all records

Other highest-scoring records for the same primary product.

CVE-2026-50152Ceph Monitor subscription handler improperly authorizes config-key store reads, exposing cluster secrets to read-only users
36Monitor
CVE-2025-30156Ceph: AES-CBC misuse in CephX and RADOSGW enables authentication bypass and credential forgery
35Monitor
CVE-2026-39944Ceph: CephX AES Authentication error
35Monitor

Published before and after this one in the same product

← EarlierCVE-2020-1700Feb 7, 2020 · A flaw was found in the way the Ceph RGW Beast front-end handles unexpected disconnects.
27Monitor
← EarlierCVE-2025-52555Jun 26, 2025 · CephFS Permission Escalation Vulnerability in Ceph Fuse mounted FS
26Monitor
← EarlierCVE-2024-48916Jul 30, 2025 · Ceph is vulnerable to authentication bypass through RadosGW
32Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
azl3 ceph 18.2.2-12 on Azure Linux 3.0	18.2.2-13	Microsoft (MSRC)
debian:ceph	20.2.4+ds-1 · Debian:14	Package registry (OSV)
red hat:ceph	2:19.2.1-423.el9cp · Red Hat:ceph_storage:8.1::el9	Package registry (OSV)
red hat:ceph-base	2:19.2.1-423.el9cp · Red Hat:ceph_storage:8.1::el9	Package registry (OSV)
red hat:ceph-base-debuginfo	2:19.2.1-423.el9cp · Red Hat:ceph_storage:8.1::el9	Package registry (OSV)
red hat:ceph-common	2:19.2.1-423.el9cp · Red Hat:ceph_storage:8.1::el9	Package registry (OSV)
red hat:ceph-common-debuginfo	2:19.2.1-423.el9cp · Red Hat:ceph_storage:8.1::el9	Package registry (OSV)
red hat:ceph-debuginfo	2:19.2.1-423.el9cp · Red Hat:ceph_storage:8.1::el9	Package registry (OSV)
red hat:ceph-debugsource	2:19.2.1-423.el9cp · Red Hat:ceph_storage:8.1::el9	Package registry (OSV)
red hat:ceph-exporter-debuginfo	2:19.2.1-423.el9cp · Red Hat:ceph_storage:8.1::el9	Package registry (OSV)
red hat:ceph-fuse	2:19.2.1-423.el9cp · Red Hat:ceph_storage:8.1::el9	Package registry (OSV)
red hat:ceph-fuse-debuginfo	2:19.2.1-423.el9cp · Red Hat:ceph_storage:8.1::el9	Package registry (OSV)
red hat:ceph-immutable-object-cache	2:19.2.1-423.el9cp · Red Hat:ceph_storage:8.1::el9	Package registry (OSV)
red hat:ceph-immutable-object-cache-debuginfo	2:19.2.1-423.el9cp · Red Hat:ceph_storage:8.1::el9	Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Not on record for this CVE: researcher credit · variant or chain candidate · public bounty program.

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
A low-privileged account is enough.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality: high · data can be read
Integrity: high · data or configuration can be modified
Availability: none

Attack vector: Network
Attack complexity: Low
Privileges required: Low
User interaction: None
Scope: Unchanged
Confidentiality impact: High
Integrity impact: High
Availability impact: None

Weakness class (CWE)

CWE-347 · Improper Verification of Cryptographic Signature

CVSS vector

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

nvd-secondary

Root cause

The verifier takes the algorithm to verify with from the token’s own header. Untrusted data ends up deciding its own verification rule.

The bug in code

The whole CWE-347 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1const claims = jwt.verify(token, publicKey);

Fixed

1const claims = jwt.verify(token, publicKey, {
2  algorithms: ["RS256"],
3  issuer: "https://id.example.com",
4  audience: "portal",
5});

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Attack patterns (CAPEC)

ATT&CK techniques

—

Change log (1)

Fix✗ → ✓Sep 28, 2026, 10:07 PM UTC

For records you follow, these changes also arrive as notifications. →

References

github.com/ceph/ceph/commit/5837aa8e60471128dbb672b0ff6f1b1feebe08a7

Show all references (2 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records