6.4

CVE-2026-5590: zephyrproject-rtos zephyr NULL Pointer Dereference

CVSS: 6.4v3.1MediumAnalyzed
Published 05-04-2026Last modified 15-10-2026
Open JSON

Vulnerability summary

CVE-2026-5590 is a medium (CVSS 6.4) NULL Pointer Dereference vulnerability in zephyrproject-rtos zephyr. EPSS estimates a 0.27% chance of exploitation in the next 30 days, higher than 18.7% of scored vulnerabilities. 1 public exploit is recorded.

Overall risk
36/100
0100
Medium · default modelHow is this calculated?
CVSS score
6.4/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.27%
0%100%
Low · +0.08 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits1github

Timeline

  1. 05-04-2026
    PublishedVulnerability first disclosed.
  2. 15-10-2026
    Last modifiedVulnerability information updated.

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.

CVSS metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

0.27%

Chance of exploitation in the next 30 days

Percentile

19%

Versus all other CVEs

30-day change

+0.08 pp

From 0.20% on 21-09-2026

21-09-202621-10-2026
EPSS score
0.27%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

1 found
  • githubUnverified

    Zephyr

    Maturity: poc

Weaknesses

CWE · root cause

Affected systems

Zephyrproject1 product
Zephyrproject-rtos1 product

2 vendors · 2 products

References

1 links