CVE-2026-98577
Received Received - Intake

NFC LLCP Service Name Length Bypass in Linux Kernel

Publication date: 2026-10-18

Last updated on: 2026-10-18

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: nfc: llcp: fix WKS SAP hijacking via prefix match in nfc_llcp_wks_sap() nfc_llcp_wks_sap() compares only service_name_len bytes, so a short service_name like "u" matches longer WKS strings like "urn:nfc:sn:snep". Fix by requiring exact length match before strncmp().

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Meta Information

Published
2026-10-18
Last Modified
2026-10-18
Generated
2026-10-18
AI Q&A
2026-10-18
EPSS Evaluated
N/A
NVD
CVE-2026-98577
EUVD
EUVD-2026-103622

Affected Vendors & Products

Showing 9 associated CPEs
Vendor Product Version / Range
Linux Linux d646960f7986fefb460a2b062d5ccc8ccfeacc3a
Linux Linux d646960f7986fefb460a2b062d5ccc8ccfeacc3a
Linux Linux d646960f7986fefb460a2b062d5ccc8ccfeacc3a
Linux Linux d646960f7986fefb460a2b062d5ccc8ccfeacc3a
Linux Linux d646960f7986fefb460a2b062d5ccc8ccfeacc3a
Linux Linux d646960f7986fefb460a2b062d5ccc8ccfeacc3a
Linux Linux d646960f7986fefb460a2b062d5ccc8ccfeacc3a
Linux Linux d646960f7986fefb460a2b062d5ccc8ccfeacc3a
Linux Linux 3.3

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Exploitability

CWE
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KEV
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CWE ID Description
CWE-UNKNOWN

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Executive Summary

This vulnerability in the Linux kernel involves a flaw in the NFC LLCP (Near Field Communication Logical Link Control Protocol) module. The function nfc_llcp_wks_sap() incorrectly compares only part of the service name, allowing a short service name like 'u' to match longer WKS strings such as 'urn:nfc:sn:snep'. This can lead to unauthorized hijacking of the Well-Known Service (WKS) SAP (Service Access Point). The fix requires an exact length match before performing the string comparison.

Detection Guidance

This vulnerability affects the Linux kernel's NFC LLCP subsystem. Detection requires checking kernel versions and NFC service configurations. Inspect running kernel version with 'uname -r' and verify if the vulnerable code path exists in the NFC stack. No direct network scanning commands are applicable.

Impact Analysis

If exploited, this vulnerability could allow an attacker to hijack NFC service access points by sending specially crafted service names. This might enable unauthorized access to NFC services, data interception, or manipulation of NFC communications. Systems using affected Linux kernel versions with NFC functionality could be at risk.

Mitigation Strategies

Apply the latest kernel security updates immediately. If updates are unavailable, disable NFC services temporarily with 'systemctl stop nfc' or unload the NFC module using 'modprobe -r nfc'. Monitor vendor advisories for patches addressing CVE-2026-98577.

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