net: ip/tcp: Null pointer dereference can be triggered by a race condition

published 2026-04-05 7 mo ago modified 2026-10-15 24 d ago also EUVD-2026-19028

cvss: 6.4; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.2%; EPSS 0.2% chance of exploitation in 30 days, percentile 10%
public exploits: 0; none known

A race condition during TCP connection teardown can cause tcp_recv() to operate on a connection that has already been released. If tcp_conn_search() returns NULL while processing a SYN packet, a NULL pointer derived from stale context data is passed to tcp_backlog_is_full() and dereferenced without validation, leading to a crash.

Patch / fix

links 1

github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-4vqm-pw… advisory

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 7 mo ago (2026-04-06)

Exploit prediction

0.20% chance of exploitation in the next 30 days, higher than 10% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-4vqm-pw24-g9jp referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	3.1	6.4	CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:H
NVD	3.1	5.3	CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

zephyrproject-rtos Zephyr

Classification

Weakness

CWE-476 NULL Pointer Dereference

References

github.com /zephyrproject-rtos/zephyr/security/advisories/GHSA-4vqm-pw24-g9jp
exploit, patch, vendor-advisory

Sources

CVE List CVE-2026-5590
NVD CVE-2026-5590

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Summary