CVE-2025-40057: ptp: Add a upper bound on max_vclocks

highCVSS 7.1CVE-2025-40057

CSIRTS triage

vendor: Linux product: Linux Kernel Denial of service

What: PTP (Precision Time Protocol) subsystem lacks upper bound validation on max_vclocks parameter.
Who is affected: Linux systems with PTP enabled and exposed to local or remote configuration.
Urgency: High priority; CVSS 7.1 indicates significant denial-of-service risk.
Action: Apply kernel patch adding upper bound validation to max_vclocks.

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

⚡ Watch Linux Kernel

Get an email when a new Linux Kernel advisory drops — max one per day, one-click unsubscribe.

Details

Source: Microsoft Security Response Center (INTL · vendor-psirt · site)
Severity: high — CVSS 7.1
Published: 2026-08-06
Exploitation: Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-40057

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-2025-400570.20% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 10% of all EPSS-scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2025-40057	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

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

high[UPDATE] [high] Linux Kernel: Multiple vulnerabilitiescert-bund

Recent advisories for ptp

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-2026-74603: In the Linux kernel, the following vulnerability has been resolved: ptp: ocp: Fix board ID ove…nvd · 2026-08-22
mediumCVE-2026-12632: Zephyr's Precision Time Protocol receive handler ptp_msg_post_recv() in subsys/net/lib/ptp/msg…nvd · 2026-08-18
unknownCVE-2026-72414: In the Linux kernel, the following vulnerability has been resolved: net: dsa: sja1105: round u…nvd · 2026-08-15
lowCVE-2026-74603: ptp: ocp: Fix board ID over-readmsrc · 2026-08-11
highCVE-2026-68134: In the Linux kernel, the following vulnerability has been resolved: ptp: ptp_s390: Add missing…nvd · 2026-08-10
unknownCVE-2026-68133: In the Linux kernel, the following vulnerability has been resolved: ice: fix PTP Call Trace du…nvd · 2026-08-10