CVE-2026-49895: IEEE 802.11 Information Disclosure Vulnerability

CVE-2026-49895 Overview

CVE-2026-49895 is an out-of-bounds read vulnerability in the get_eht_operation_channel_width function of ieee802_11_common.c. The flaw stems from an incorrect bounds check in code that parses IEEE 802.11 Extremely High Throughput (EHT) operation elements. An adjacent-network attacker within Wi-Fi range can trigger the read without authentication or user interaction. Successful exploitation results in information disclosure from adjacent process memory. Android Security Bulletin 2026-09-01 addresses the issue.

Critical Impact
Adjacent-network attackers can read out-of-bounds memory from the Wi-Fi stack without user interaction, potentially exposing sensitive process data.

Affected Products

Android platform components processing IEEE 802.11 EHT operation elements
ieee802_11_common.c in the Wi-Fi supplicant/hostapd codebase
Devices covered by Android Security Bulletin 2026-09-01

Discovery Timeline

2026-09-08 - CVE-2026-49895 published to NVD
2026-09-10 - Last updated in NVD database

Technical Details for CVE-2026-49895

Vulnerability Analysis

The vulnerability resides in get_eht_operation_channel_width, a helper that parses the EHT Operation Information field defined in the IEEE 802.11be amendment. The function reads channel-width and channel-index fields from a beacon or probe response element without correctly validating that the element buffer contains the expected number of bytes. When the element is shorter than assumed, the function reads past the allocated boundary and returns data derived from adjacent heap or stack memory. The disclosed bytes may be surfaced to userspace through Wi-Fi scan results or logging paths, giving an adjacent attacker a mechanism to leak process memory.

Root Cause

The defect is classified under [CWE-120] (Buffer Copy without Checking Size of Input). The bounds check preceding the field access in get_eht_operation_channel_width does not correctly compare the parser cursor against the actual element length, so undersized EHT operation elements are treated as if they contain full-length data.

Attack Vector

Exploitation requires the attacker to be on an adjacent Wi-Fi network within radio range of the victim device. The attacker transmits crafted 802.11 management frames containing a malformed EHT Operation element. No credentials on the target device and no user interaction are required. The impact is limited to information disclosure; the flaw does not by itself grant code execution.

No public proof-of-concept code is available. Refer to the Android Security Bulletin 2026-09-01 for authoritative technical detail.

Detection Methods for CVE-2026-49895

Indicators of Compromise

Malformed 802.11 beacon or probe response frames containing truncated EHT Operation elements observed by wireless monitoring sensors.
Unexpected Wi-Fi supplicant crashes, restarts, or memory-parsing errors in device logs coinciding with scans of nearby SSIDs.
Rogue access points advertising EHT (Wi-Fi 7) capabilities from unknown or short-lived BSSIDs in proximity to enterprise-managed devices.

Detection Strategies

Deploy wireless intrusion detection sensors that parse 802.11be management frames and flag EHT Operation elements with inconsistent length fields.
Monitor Android device telemetry for wpa_supplicant and Wi-Fi HAL error entries referencing EHT parsing failures.
Correlate proximity-based anomalies, such as sudden appearance of unknown APs with EHT capability bits set, with device scan events.

Monitoring Recommendations

Ingest wireless controller and IDS logs into a centralized analytics platform to baseline expected EHT-capable APs in each site.
Track Android patch-level compliance across the fleet to confirm devices carry the 2026-09-01 security patch level or later.
Alert on repeated Wi-Fi disconnect and rescan cycles that could indicate malformed frame injection attempts.

How to Mitigate CVE-2026-49895

Immediate Actions Required

Apply the Android security patch level 2026-09-01 or later on all managed devices.
Inventory devices that lack an available vendor patch and prioritize firmware updates through the OEM.
Restrict use of untrusted Wi-Fi networks on unpatched devices, particularly in public or high-density environments.

Patch Information

The fix ships as part of Android Security Bulletin 2026-09-01. Device manufacturers integrate the corrected bounds check in get_eht_operation_channel_width within ieee802_11_common.c and distribute it through their standard OTA update channels. Consult the Android Security Bulletin 2026-09-01 for the authoritative list of fixed components and source references.

Workarounds

Disable Wi-Fi on affected devices when operating in untrusted radio environments until the patch is applied.
Use enterprise mobility management policies to restrict association to known-good SSIDs and disable auto-join for open networks.
Enforce Wi-Fi 6 or earlier connectivity where operationally feasible to reduce exposure to EHT element parsing paths.

bash

# Verify Android security patch level on a managed device
adb shell getprop ro.build.version.security_patch
# Expected output: 2026-09-01 or later