PT-2025-43618 · Linux+1 · Linux Kernel+1

Published 2025-10-24 · Updated 2026-03-14 · CVE-2025-40022

Positive Technologies (AI Summary)

CVSS v2.0

4.9

Medium

Base vector

AV:A/AC:M/Au:S/C:P/I:P/A:P

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

Description The Linux kernel contains an issue within the crypto/af alg subsystem. A change introduced by commit 1b34cbbf4f01 altered data types from bool to 1-bit bitfields of type u32. This modification caused incorrect assignments to fields named 'more' and 'merge', as values greater than 1 were being assigned, relying on C's implicit conversion to boolean. The use of 1-bit bitfields resulted in unintended behavior where 0 was assigned instead of 1 in certain cases. The issue is resolved by reverting the data type back to bool.

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

Exploit

Incorrect Type Conversion or Cast

Weakness Enumeration

CWE-704

Related Identifiers

BDU:2026-02773

CVE-2025-40022

DLA-4379-1

DLA-4404-1

DSA-6053-1

ECHO-A046-AA9B-C514

MGASA-2025-0309

MGASA-2025-0310

Affected Products

Debian

Linux Kernel

References · 51

• 🔥 https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/40xxx/CVE-2025-40022.json · Exploit
• https://nvd.nist.gov/vuln/detail/CVE-2025-40022 · Security Note
• https://osv.dev/vulnerability/DEBIAN-CVE-2025-40022 · Vendor Advisory
• https://osv.dev/vulnerability/BELL-CVE-2025-40022 · Vendor Advisory
• https://wiki.astralinux.ru/astra-linux-se47-bulletin-2026-0518SE47 · Vendor Advisory
• https://linux.oracle.com/errata/ELSA-2026-50071.html · Vendor Advisory
• https://bdu.fstec.ru/vul/2026-02773 · Security Note
• https://osv.dev/vulnerability/ROOT-OS-DEBIAN-11-CVE-2025-40022 · Vendor Advisory
• https://linux.oracle.com/errata/ELSA-2025-28048.html · Vendor Advisory
• https://wiki.astralinux.ru/astra-linux-se18-bulletin-2026-0224SE18 · Vendor Advisory
• https://osv.dev/vulnerability/ROOT-OS-DEBIAN-13-CVE-2025-40022 · Vendor Advisory
• https://security-tracker.debian.org/tracker/CVE-2025-40022 · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2025-40022 · Security Note
• https://wiki.astralinux.ru/astra-linux-se17-bulletin-2026-0302SE17MD · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2025-40022 · Vendor Advisory