CVE-2025-30156: Ceph: AES-CBC misuse in CephX and RADOSGW enables authentication bypass and credential forgery

highCVSS 8.9CVE-2025-30156

CSIRTS triage

vendor: Ceph product: Ceph Authentication bypass

What: AES-CBC misuse in CephX and RADOSGW enables authentication bypass and credential forgery.
Who is affected: Ceph deployments using CephX authentication and RADOSGW are affected.
Urgency: High urgency given the CVSS score of 8.9 and the ability to bypass authentication and forge credentials.
Action: Update Ceph to a version that corrects the AES-CBC implementation in CephX and RADOSGW.

AI-assisted analysis generated from the source advisory — verify against the original.

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Details

Source: Microsoft Security Response Center (INTL · vendor-psirt · site)
Severity: high — CVSS 8.9
Published: 2026-08-11
Exploitation: Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-30156

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2025-301560.09% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 1% of all EPSS-scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2025-30156	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

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