ptp: Potential Denial of Service via PTP Interval Shift

published 2026-05-22 5 mo ago modified 2026-10-15 24 d ago also EUVD-2026-31413

cvss: 6.5; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.3%; EPSS 0.3% chance of exploitation in 30 days, percentile 22%
public exploits: 0; none known

A bitwise shift vulnerability in Zephyr's PTP subsystem allows a remote attacker to cause undefined behavior and potential system crashes. An attacker sends a crafted PTP_MSG_MANAGEMENT message to set an unvalidated negative log_announce_interval value in the port's data set. When a subsequent PTP_MSG_ANNOUNCE message is processed, port_timer_set_timeout_random computes a timeout as NSEC_PER_SEC >> -log_seconds; if the attacker-supplied value is sufficiently negative (e.g., -127), the shift amount exceeds the 64-bit integer width, triggering undefined behavior in C. This can cause a system crash via a compiler-generated illegal instruction trap on some architectures, or produce an erroneous zero timeout leading to resource starvation loops or other logical errors.

Patch / fix

links 1

github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-3v98-45… advisory

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 5 mo ago (2026-05-22)

Exploit prediction

0.30% chance of exploitation in the next 30 days, higher than 22% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-3v98-458v-388r referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CISA ADP	3.1	6.5	CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA	3.1	6.5	CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

zephyrproject-rtos Zephyr

Classification

Weakness

CWE-1335 Incorrect Bitwise Shift of Integer

References

github.com /zephyrproject-rtos/zephyr/security/advisories/GHSA-3v98-458v-388r
exploit, patch, vendor-advisory

Sources

CVE List CVE-2026-5072
NVD CVE-2026-5072

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Summary