Linux Kernel up to 7.1.8 rtl8723bs OnAuthClient buffer overflow

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.
9.5	$5k-$25k	2.59

Summaryinfo

A vulnerability classified as very critical was found in Linux Kernel up to 7.1.8. This impacts the function OnAuthClient of the component rtl8723bs. Such manipulation leads to buffer overflow. This vulnerability is documented as CVE-2026-74649. The attack can be executed remotely. There is not any exploit available.

Detailsinfo

A vulnerability, which was classified as very critical, has been found in Linux Kernel up to 7.1.8. Affected by this issue is the function OnAuthClient of the component rtl8723bs. The manipulation with an unknown input leads to a buffer overflow vulnerability. Using CWE to declare the problem leads to CWE-120. The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer, leading to a buffer overflow. Impacted is confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: staging: rtl8723bs: fix missing shared-key auth challenge length check The WEP shared-key authentication handler uses the challenge-text element's attacker-controlled length without checking it against the fixed 128-byte chg_txt buffer. In OnAuthClient() the length from rtw_get_ie() - up to 255 - is used to perform memcpy() into the 128-byte pmlmeinfo->chg_txt, so a malicious AP sending a malformed WLAN_EID_CHALLENGE element can overflow/underfill chg_txt by up to 127 bytes. It is reachable over the air, before association, during shared-key authentication. In the case of an overflow, the driver can write out of bounds. In the case of an underfill, the driver can echo stale buffer memory. The challenge text is defined to be exactly 128 octets, which is already provided as the WLAN_AUTH_CHALLENGE_LEN define; require the element to be exactly that length before use.

The advisory is shared for download at git.kernel.org. This vulnerability is handled as CVE-2026-74649 since 08/15/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 08/22/2026).

Upgrading to version 5.15.216, 6.1.183, 6.6.152, 6.12.104, 6.18.45 or 7.1.9 eliminates this vulnerability. Applying the patch 39ae1033071001af9bb4573ebdbb43bbbe88f749/4d018e7d7d908bdfcb5ecfa922b1d5cb9ddb3722/4ba402fd47009d20e51dbfc934abb562098ea35b/87c2f073d2aaea041d531b8e579c47570b54b3b7/a28a4b0592e4a37ea471bc0d308513a93133ce7e/6235b5156b48ed5d1ce3410d8f0b2fd67d30d944/2c56ef658ac8c6bca36bc5574715e8f717207c6c is able to eliminate this problem.

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Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.15.215
• 6.1.182
• 6.6.151
• 6.12.103
• 6.18.0
• 6.18.1
• 6.18.2
• 6.18.3
• 6.18.4
• 6.18.5
• 6.18.6
• 6.18.7
• 6.18.8
• 6.18.9
• 6.18.10
• 6.18.11
• 6.18.12
• 6.18.13
• 6.18.14
• 6.18.15
• 6.18.16
• 6.18.17
• 6.18.18
• 6.18.19
• 6.18.20
• 6.18.21
• 6.18.22
• 6.18.23
• 6.18.24
• 6.18.25
• 6.18.26
• 6.18.27
• 6.18.28
• 6.18.29
• 6.18.30
• 6.18.31
• 6.18.32
• 6.18.33
• 6.18.34
• 6.18.35
• 6.18.36
• 6.18.37
• 6.18.38
• 6.18.39
• 6.18.40
• 6.18.41
• 6.18.42
• 6.18.43
• 6.18.44
• 7.1.0
• 7.1.1
• 7.1.2
• 7.1.3
• 7.1.4
• 7.1.5
• 7.1.6
• 7.1.7
• 7.1.8

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: 10.0
VulDB Meta Temp Score: 9.5

VulDB Base Score: 10.0
VulDB Temp Score: 9.5
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: Buffer overflow
CWE: CWE-120 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
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: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.15.216/6.1.183/6.6.152/6.12.104/6.18.45/7.1.9
Patch: 39ae1033071001af9bb4573ebdbb43bbbe88f749/4d018e7d7d908bdfcb5ecfa922b1d5cb9ddb3722/4ba402fd47009d20e51dbfc934abb562098ea35b/87c2f073d2aaea041d531b8e579c47570b54b3b7/a28a4b0592e4a37ea471bc0d308513a93133ce7e/6235b5156b48ed5d1ce3410d8f0b2fd67d30d944/2c56ef658ac8c6bca36bc5574715e8f717207c6c

Timelineinfo

08/15/2026 CVE reserved
08/22/2026 +7 days Advisory disclosed
08/22/2026 +0 days VulDB entry created
08/22/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-74649 (🔒)
GCVE (CVE): GCVE-0-2026-74649
GCVE (VulDB): GCVE-100-394436

Entryinfo

Created: 08/22/2026 18:40
Changes: 08/22/2026 18:40 (59)
Complete: 🔍
Cache ID: 216::103

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