CVE-2026-5590: zephyrproject-rtos Zephyr · NULL Pointer Dereference
Affects zephyrproject-rtos ZephyrSource CVE Database V5
Not known to be exploited · CVSS 6.4 Medium : upgrade to 4.3.1 when convenient.
Data as of 30 Oct 2026, 06:59 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 9% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 4.3.1
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:HExploitation evidence
Disclosed: evidence found.
CVE published 5 Apr 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.
What to do
Upgrade zephyrproject-rtos Zephyr to 4.3.1.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| zephyrproject-rtosZephyr | Affected
| Fixed in
|
GitHubzephyrproject-rtos/zephyrpkg:github/zephyrproject-rtos/zephyrOther threats | Affected
| Fixed in– |
GitHubZephyrpkg:github/ZephyrOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
No vendor advisory or patch links are currently provided, so no specific mitigation steps can be recommended beyond awaiting an official fix.
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.