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 CephX authentication protocol encrypts tickets with AES-128-CBC in an unauthenticated mode that uses a hard-coded initialization vector and no message authentication, allowing an attacker to forge credentials and gain cluster-wide access. Because the ciphertext is malleable and the monitor will encrypt attacker-chosen entity names, an attacker holding one low-privilege key and able to observe CephX traffic can use the monitor as an encryption oracle and splice ciphertext blocks into valid tickets for privileged entities such as Manager, MDS, and OSD. The same lack of authentication also lets an attacker with CephX permissions escalate privileges by flipping a single bit in a service ticket to set its allow_all field to true. This issue is fixed in versions 20.2.4 and 19.2.6.
CVE-2025-30156
This high-severity CVE scores 8.9 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.1%, top 99% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
- High severity, but no confirmed exploitation yet
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 8.9
- EG Score
- 8.9(medium)
- EG Risk
- 45(Track)EG Risk 45/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity89% × 45%Exploitation0% × 40%Automatability30% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 0%
- EPSS %ILE
- 1%
- KEV
- Not listed
Published
August 27, 2026
Last Modified
August 28, 2026
Advisory Details (3)
Auto-updated Aug 27, 2026commit 3078188a7bdd (ceph/ceph)
Fix landed in ceph/ceph commit 3078188a7bdd — awaiting tagged release
https://github.com/ceph/ceph/commit/3078188a7bdd89e2975280f2a906c71c2f6effd6commit 2ba086255de0 (ceph/ceph)
Fix landed in ceph/ceph commit 2ba086255de0 — awaiting tagged release
https://github.com/ceph/ceph/commit/2ba086255de09c8b95177717cc7e9dd4377e2f0fAES-CBC misuse in CephX facilitating authentication bypass · Advisory · ceph/ceph · GitHub
https://github.com/ceph/ceph/security/advisories/GHSA-7q3q-3975-qw3qWeakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 6× in last 7d / 6× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-08-30 01:21 UTCEPSS rescore
- 2026-08-28 23:53 UTCEG score recompute
- 2026-08-28 21:40 UTCEPSS rescore
- 2026-08-28 00:31 UTCEG score recompute
- 2026-08-27 23:23 UTCEG score recompute
- 2026-08-27 23:22 UTCMITRE cvelistV5first tracked
Related CVEs(same CWE)
Same CWE
10 shownCWE-327
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Dependency Blast Radius
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