SB2026051268 - Local privilege escalation in QNAP QuTS products

Description

This security bulletin contains information about 2 vulnerabilities.

1) Resource management error (CVE-ID: CVE-2026-43284)

CWE-ID: CWE-399 - Resource Management Errors

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:A/U:Amber

The vulnerability allows a local user to escalate privileges on the system.

The xfrm-ESP Page-Cache Write vulnerability exists due to improper management of internal resources in esp_input() function in net/ipv4/esp4.c and esp6_input() function in net/ipv6/esp6.c. A local user can execute arbitrary code with root privileges. 

Note, this is one of two vulnerabilities reported as Dirty Frag.

2) Resource management error (CVE-ID: CVE-2026-43500)

CWE-ID: CWE-399 - Resource Management Errors

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:A/U:Amber

The vulnerability allows a local user to escalate privileges on the system.

The RxRPC Page-Cache Write vulnerability exists due to improper management of internal resources. A local user can execute arbitrary code with root privileges.

Note, this vulnerability is one of two issues described as Dirty Frag.

Remediation

Cybersecurity Help is not aware of any official remediation provided by the vendor.

References

• https://www.qnap.com/en/security-advisory/qsa-26-17