CVE-2026-68159: libceph: bound pg_{temp,upmap,upmap_items} length to CEPH_PG_MAX_SIZE

mediumCVSS 6.5CVE-2026-68159

CSIRTS triage

vendor: Ceph product: libceph Denial of service

What: The libceph library fails to bound pg_temp, pg_upmap, and pg_upmap_items list lengths, allowing denial-of-service through oversized cluster maps.
Who is affected: Ceph client systems running vulnerable libceph versions.
Urgency: Medium; CVSS 6.5 indicates moderate severity requiring timely patching.
Action: Update libceph library with bounds checking on cluster map parameters.

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 6.5
Published: 2026-08-11
Exploitation: Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-68159

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-2026-681590.76% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 52% of all EPSS-scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-68159	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

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

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.

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