PT-2025-9967 · Linux+8 · Linux Kernel+8

Noam Rathaus · Published 2025-01-30 · Updated 2026-04-20 · CVE-2025-21826

Positive Technologies (AI Summary)

CVSS v3.1

5.5

Medium

Base vector

AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description A resolved issue in the Linux kernel involves a mismatch between the sum of field lengths and the set key length in the netfilter nf tables component. The field length description provides the length of each separated key field, which is rounded up to 32-bits to calculate the pipapo rule width. However, register-based arithmetics can still combine mismatching set key lengths and field length descriptions, potentially leading to incorrect pipapo widths.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Exploit

Weakness Enumeration

CWE-682

Related Identifiers

ALSA-2025:20095

ALSA-2025:20518

BDU:2025-12280

CVE-2025-21826

DLA-4102-1

DLA-4178-1

INFSA-2025_20518

OESA-2025-1446

OESA-2025-1450

RHSA-2025:20095

RHSA-2025:20518

RHSA-2025_20518

USN-7510-1

USN-7510-2

USN-7510-3

USN-7510-4

USN-7510-5

USN-7510-6

USN-7510-7

USN-7510-8

USN-7511-1

USN-7511-2

USN-7511-3

USN-7512-1

USN-7521-1

USN-7521-2

USN-7521-3

USN-7593-1

USN-7602-1

USN-7651-1

USN-7651-2

USN-7651-3

USN-7651-4

USN-7651-5

USN-7651-6

USN-7652-1

USN-7653-1

USN-7737-1

Affected Products

Almalinux

Astra Linux

Debian

Linuxmint

Linux Kernel

Red Hat

Red Os

Rocky Linux

Ubuntu

References · 1000

• 🔥 https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/21xxx/CVE-2025-21826.json · Exploit
• https://ubuntu.com/security/CVE-2025-21666 · Vendor Advisory
• https://git.kernel.org/stable/c/1b9335a8000fb70742f7db10af314104b6ace220 · Patch
• https://ubuntu.com/security/CVE-2025-22044 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2024-56587 · Security Note
• https://ubuntu.com/security/notices/USN-7593-1 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2024-56574 · Security Note
• https://ubuntu.com/security/CVE-2024-58052 · Vendor Advisory
• https://ubuntu.com/security/CVE-2025-21743 · Vendor Advisory
• https://ubuntu.com/security/CVE-2025-21670 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2024-58013 · Security Note
• https://ubuntu.com/security/CVE-2024-53168 · Vendor Advisory
• https://ubuntu.com/security/CVE-2025-21922 · Vendor Advisory
• https://ubuntu.com/security/CVE-2025-21838 · Vendor Advisory
• https://ubuntu.com/security/CVE-2025-21674 · Vendor Advisory