VDB-355387 · CVE-2026-5590 · GHSA-4vqm-pw24-g9jp

zephyrproject-rtos Zephyr up to 4.3 TCP Connection tcp_recv null pointer dereference

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
5.8	$0-$5k	0.00

Summaryinfo

A vulnerability marked as problematic has been reported in zephyrproject-rtos Zephyr up to 4.3. Affected is the function tcp_recv of the component TCP Connection Handler. This manipulation causes null pointer dereference. This vulnerability is tracked as CVE-2026-5590. The attack is possible to be carried out remotely. No exploit exists.

Detailsinfo

A vulnerability has been found in zephyrproject-rtos Zephyr up to 4.3 and classified as problematic. Affected by this vulnerability is the function tcp_recv of the component TCP Connection Handler. The manipulation with an unknown input leads to a null pointer dereference vulnerability. The CWE definition for the vulnerability is CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. As an impact it is known to affect availability. The summary by CVE is:

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.

It is possible to read the advisory at github.com. This vulnerability is known as CVE-2026-5590 since 04/05/2026. The exploitation appears to be difficult. The attack can be launched remotely. Technical details of the vulnerability are known, but there is no available exploit.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Type

Project Management Software

Vendor

zephyrproject-rtos

Name

Zephyr

Version

License

open-source

Website

Product: https://github.com/zephyrproject-rtos/zephyr/

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.8
VulDB Meta Temp Score: 5.8

VulDB Base Score: 5.3
VulDB Temp Score: 5.3
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 6.4
CNA Vector (zephyr): 🔒

CVSSv2info

AV	AC	Au	C	I	A
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💳	💳	💳	💳	💳	💳
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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Null pointer dereference
CWE: CWE-476 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Timelineinfo

04/05/2026 Advisory disclosed
04/05/2026 +0 days CVE reserved
04/05/2026 +0 days VulDB entry created
04/05/2026 +0 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: GHSA-4vqm-pw24-g9jp
Status: Confirmed

CVE: CVE-2026-5590 (🔒)
GCVE (CVE): GCVE-0-2026-5590
GCVE (VulDB): GCVE-100-355387

Entryinfo

Created: 04/05/2026 07:10
Changes: 04/05/2026 07:10 (65)
Complete: 🔍
Cache ID: 216:EFC:103