{"id":"CVE-2026-5590","title":"A race condition during TCP connection teardown can cause tcp_recv() to operate on a connection that has already been released","summary":"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 da…","severity":"medium","cvss":6.4,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:H","cwe":["CWE-476"],"vendor":"zephyrproject","product":"zephyr","affected":["zephyr <= 4.3.0"],"published":"2026-04-05","updated":"2026-07-08","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-5590","references":[{"url":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-4vqm-pw24-g9jp","label":"vulnerabilities@zephyrproject.org"}],"tags":["nvd"],"epss":0.00198,"epssPercentile":0.09929,"ingestedAt":"2026-07-08T13:51:10.455Z","slug":"CVE-2026-5590","body":"## Overview\n\nA 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.\n\n## Affected\n\n- `zephyr <= 4.3.0`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":35,"depthScoreParts":{"impact":35.2,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}