Reference page — cumulative record through Monday, October 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2026-5590

CVE-2026-5590MEDIUM

zephyrproject-rtos Zephyr — net: ip/tcp: Null pointer dereference can be triggered by a race condition

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   N   H   L   N  U  N  N  H    5.3   .0027   18.5     —

AFFECTED
  Product  Versions     Fixed
  Zephyr   unspecified  —

TIMELINE
  Apr 5   Reserved by zephyr
  Apr 5   Published (CNA: zephyr)
  Oct 15  EXPLOIT PUBLISHED — CVE-2026-5590 (zephyrproject-rtos Zephyr). Public exploit reference added.
  Oct 15  RESCORED — CVE-2026-5590 (zephyrproject-rtos Zephyr). CVSS 6.4 → 5.3 (NVD).

CWE-476 · CNA: zephyr · CVSS v3.1 · 1 reference · NVD status: Analyzed

Description

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.

Lifecycle

Complete event history — 4 events, chronological
Date	Event	Detail
April 5, 2026	Reserved	Reserved by zephyr
April 5, 2026	Published	Published (CNA: zephyr)
October 15, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-5590 (zephyrproject-rtos Zephyr). Public exploit reference added.
October 15, 2026	RESCORED	RESCORED — CVE-2026-5590 (zephyrproject-rtos Zephyr). CVSS 6.4 → 5.3 (NVD).

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
zephyrproject-rtos	Zephyr	—	—	—

Weaknesses

CWE-476

References (1)

https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-4vqm-pw24-g9jp [Exploit, Patch, Vendor Advisory]

Authoritative record: CVE-2026-5590 at cve.org

Vendors: zephyrproject-rtos

Weaknesses: CWE-476

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-5590 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Monday, October 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.