Bug 2554979 (CVE-2026-98577)

Summary: CVE-2026-98577 kernel: nfc: llcp: fix WKS SAP hijacking via prefix match in nfc_llcp_wks_sap()
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's Near Field Communication (NFC) subsystem. In the Logical Link Control Protocol (LLCP) implementation, the kernel validates service names using only the length of the provided name instead of verifying an exact match. A local attacker could exploit this flaw by supplying a shortened service name to improperly bind to and hijack a Well-Known Service Access Point (WKS SAP). This issue could allow an attacker to intercept communications intended for legitimate NFC services or cause a denial of service.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-10-18 15:37:07 UTC 
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().