CVE-2026-74650
Received Received - Intake

Out-of-Bounds Read in Linux Kernel RTL8723BS WiFi Driver

Vulnerability report for CVE-2026-74650, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.

Publication date: 2026-08-22

Last updated on: 2026-08-22

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: staging: rtl8723bs: fix OOB read in WMM_param_handler() WMM_param_handler() copies a fixed-size WMM parameter element out of a received information element without checking that the element is long enough, causing an out-of-bounds read for a short WMM IE. The handler reads sizeof(struct WMM_para_element) (18) bytes at pIE->data + 6, so it requires pIE->length to be at least 24 (WLAN_WMM_LEN), but it never validates the length. Two of its three callers reach it after matching only the WMM OUI: OnAssocRsp() in rtw_mlme_ext.c matches a 6-byte OUI, and join_cmd_hdl() matches a 4-byte OUI, before calling the handler. A vendor-specific IE carrying the WMM OUI but a length between 6 and 23, placed in an association response or in the IE blob handed to join_cmd_hdl(), passes the OUI check and then makes the memcmp() and memcpy() at pIE->data + 6 read past the end of the element. OnAssocRsp() parses a frame received from the AP, so this is reachable from a remote peer. The remaining caller in rtw_wlan_util.c already guards the handler with "pIE->length == WLAN_WMM_LEN". Move the equivalent check into the handler itself so every caller is covered; the sibling IE handlers in the same parsing loop (HT_caps_handler(), HT_info_handler(), ERP_IE_handler()) likewise bound their accesses by pIE->length.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published
2026-08-22
Last Modified
2026-08-22
Generated
2026-08-22
AI Q&A
2026-08-22
EPSS Evaluated
N/A
NVD
EUVD

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
linux_kernel linux_kernel *

Helpful Resources

Exploitability

CWE
CWE Icon
KEV
KEV Icon
CWE ID Description
CWE-UNKNOWN

Attack-Flow Graph

AI Quick Actions

Instant insights powered by AI
Executive Summary

This is an out-of-bounds read vulnerability in the Linux kernel's staging driver for RTL8723BS Wi-Fi chips. The issue occurs in the WMM_param_handler() function, which copies a fixed-size WMM parameter without validating the input length. If a maliciously crafted WMM information element (IE) with insufficient length is provided, the function reads past the end of the allocated memory, potentially exposing sensitive data or causing system instability.

Detection Guidance

This vulnerability involves an out-of-bounds read in the Linux kernel's WMM_param_handler() function. Detection requires checking for vulnerable kernel versions and inspecting network traffic for malformed WMM information elements. Use 'uname -a' to check kernel version and 'tcpdump' or 'Wireshark' to analyze network frames for WMM IEs with lengths between 6 and 23 bytes.

Impact Analysis

An attacker within wireless range could exploit this flaw by sending a specially crafted network frame to a vulnerable system. This may lead to information disclosure, denial-of-service conditions, or in rare cases, privilege escalation. Systems using affected Linux kernel versions with the RTL8723BS driver are at risk.

Mitigation Strategies

Immediately update your Linux kernel to a patched version that includes the fix for this vulnerability. If updating is not immediately possible, consider disabling the affected driver module (rtl8723bs) or restricting network access to trusted sources until the patch can be applied.

Chat Assistant

Ask questions about this CVE
Hi! I’m here to help you understand CVE-2026-74650. Ask me anything about the vulnerability, its impact, or mitigation strategies.
0/70

EPSS Chart