The IEEE 1588 (PTP) port implementation in subsys/net/lib/ptp/port.c adopted the logMessageInterval field of a received DelayResp message…
CVE-2026-87042
The IEEE 1588 (PTP) port implementation in subsys/net/lib/ptp/port.c adopted the logMessageInterval field of a received DelayResp message without any validation. portdelayrespmsgprocess() stored the raw wire value (a full-range int8t) into portds.logmindelayreqinterval, and that value is later used as a shift count by porttimersettimeout() when the DelayReq timer is armed. Values below about -30 truncate the computed timeout to zero, and values with a magnitude of 64 or more perform an undefined shift of a uint64t; the standards-defined "not applicable" encoding 0x7F fell into the latter case as well. PTP messages are received over unauthenticated link-local traffic (UDP multicast on 224.0.1.129, IPv6 multicast, or raw IEEE 802.3), and the handler accepts a DelayResp from any sender as long as the port is a time receiver using the end-to-end delay mechanism and the message echoes the port identity and a pending sequence id — both of which the victim itself broadcasts in its DelayReq. Any node on the same link can therefore inject a single crafted DelayResp, or simply become the time transmitter and advertise the bogus interval. Once the delay timer is armed with a zero timeout,…
Assessment
- CVSS
- 6.5 (v3.1)
- Severity
- Medium
- Known exploited
- Not listed in CISA KEV
- Exploit availability
- Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
- Published
- 10 November 2026
- Last updated
- 10 November 2026
- Affected
- zephyrproject · Zephyr
- Assigner
- zephyr
CVSS vectorCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
At the source
References
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