CVE-2026-68156: libceph: refresh auth->authorizer_buf{,_len} after authorizer update

mediumCVSS 5.3CVE-2026-68156

CSIRTS triage

vendor: Linux product: Linux Kernel Authentication bypass

What: The Ceph authentication authorizer buffer is not refreshed after update, allowing stale authentication credentials to be used.
Who is affected: Linux systems running libceph with Ceph cluster authentication enabled.
Urgency: Medium priority; authentication bypass weakens security posture but requires active Ceph cluster interaction.
Action: Apply Linux kernel patch that refreshes auth->authorizer_buf after authorizer update in libceph.

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: medium — CVSS 5.3
Published: 2026-08-11
Exploitation: Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-68156

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-2026-681560.68% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 50% of all EPSS-scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-68156	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

criticalCVE-2026-68156: In the Linux kernel, the following vulnerability has been resolved: libceph: refresh auth->aut…nvd

Recent advisories for libceph

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

highCVE-2026-68433: In the Linux kernel, the following vulnerability has been resolved: libceph: bound get_version…nvd · 2026-08-12
mediumCVE-2026-68154: libceph: reject zero bucket types in crush_decodemsrc · 2026-08-11
criticalCVE-2026-68153: libceph: remove debugfs files before client teardownmsrc · 2026-08-11
lowCVE-2026-68433: libceph: bound get_version reply decode to front lenmsrc · 2026-08-11
highCVE-2026-68082: libceph: fix two unsafe bare decodes in decode_lockers()msrc · 2026-08-11
mediumCVE-2026-68158: libceph: Fix multiplication overflow in decode_new_up_state_weight()msrc · 2026-08-11