VDB-329771 · CVE-2025-40022 · Nessus 274816

Linux Kernel up to 6.1.154/6.6.108/6.12.49/6.16.9 af_alg privilege escalation

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.
5.3	$0-$5k	0.00

Summaryinfo

A vulnerability, which was classified as critical, has been found in Linux Kernel up to 6.1.154/6.6.108/6.12.49/6.16.9. This affects an unknown part of the component af_alg. The manipulation leads to an unknown weakness. This vulnerability is documented as CVE-2025-40022. There is not any exploit available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Linux Kernel up to 6.1.154/6.6.108/6.12.49/6.16.9. This issue affects an unknown functionality of the component af_alg. The impact remains unknown. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: crypto: af_alg - Fix incorrect boolean values in af_alg_ctx Commit 1b34cbbf4f01 ("crypto: af_alg - Disallow concurrent writes in af_alg_sendmsg") changed some fields from bool to 1-bit bitfields of type u32. However, some assignments to these fields, specifically 'more' and 'merge', assign values greater than 1. These relied on C's implicit conversion to bool, such that zero becomes false and nonzero becomes true. With a 1-bit bitfields of type u32 instead, mod 2 of the value is taken instead, resulting in 0 being assigned in some cases when 1 was intended. Fix this by restoring the bool type.

It is possible to read the advisory at git.kernel.org. The identification of this vulnerability is CVE-2025-40022 since 04/16/2025. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 02/02/2026).

The vulnerability scanner Nessus provides a plugin with the ID 274816 (Debian dsa-6053 : affs-modules-6.1.0-37-4kc-malta-di - security update), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.1.155, 6.6.109, 6.12.50 or 6.16.10 eliminates this vulnerability. Applying the patch 3a21698ace915a445bce2d0dcfc84b6d2199baf7/d382d6daf0184490f366562469a5673f65ee2662/54506c6335690f4ef1b9f154e34f5a604c72c1ed/8703940bd30b5ad94408d28d7192db2491cd3592/316b090c2fee964c307a634fecc7df269664b158/fbe96bd25423e61273d8831e995260b429d850b6/d0ca0df179c4b21e2a6c4a4fb637aa8fa14575cb is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (274816) and CERT Bund (WID-SEC-2025-2407). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Affected

Debian Linux
Google Cloud Platform
Amazon Linux 2
Ubuntu Linux
SUSE Linux
Oracle Linux
SUSE openSUSE
Open Source Linux Kernel
Dell NetWorker

Productinfo

Type

Operating System

Vendor

Linux

Name

Kernel

Version

License

open-source

Website

Vendor: https://www.kernel.org/

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.5
VulDB Meta Temp Score: 5.3

VulDB Base Score: 5.5
VulDB Temp Score: 5.3
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

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

Exploitinginfo

Class: Privilege escalation
CWE: Unknown
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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

Nessus ID: 274816
Nessus Name: Debian dsa-6053 : affs-modules-6.1.0-37-4kc-malta-di - security update

Threat Intelligenceinfo

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

Countermeasuresinfo

Timelineinfo

04/16/2025 CVE reserved
10/24/2025 +191 days Advisory disclosed
10/24/2025 +0 days VulDB entry created
02/02/2026 +101 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2025-40022 (🔒)
GCVE (CVE): GCVE-0-2025-40022
GCVE (VulDB): GCVE-100-329771
CERT Bund: WID-SEC-2025-2407 - Linux Kernel: Mehrere Schwachstellen ermöglichen Denial of Service

Entryinfo

Created: 10/24/2025 15:27
Updated: 02/02/2026 10:43
Changes: 10/24/2025 15:27 (57), 10/28/2025 09:54 (7), 11/12/2025 08:28 (2), 12/09/2025 10:18 (1), 02/02/2026 10:43 (1)
Complete: 🔍
Cache ID: 216::103

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