Prefix match lets NFC LLCP service names hijack well-known SAPs
Key facts
- Attack vector
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- Privileges required
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- User interaction
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- Attack complexity
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- Impact type
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- Confidentiality · integrity · availability
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- Fix status
- Fixed
No CVSS vector from any source. Fix status from CNA.
Summary
The Linux kernel NFC LLCP code is affected from 3.3 until the fixes are applied. The function nfc_llcp_wks_sap() compares only as many bytes as the service name length, so a short service name such as "u" matches longer well-known service names such as "urn:nfc:sn:snep" and takes over their service access point.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
Description from the CNA
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().
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
Remediation
Fixed versions for Linux kernel are 5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.112, 6.18.55, 7.2.9 and 7.3. The fix checks for an exact service name length match before the string comparison.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
- Fix · CNA Linux (Linux) Fixed in 5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.112, 6.18.55, 7.2.9, 7.3
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
Not affected: 7 products
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4
- Red Hat OpenShift Container Platform 5
Timeline
- 2026-10-18 Threatist record created from CVE-2026-98577
- 2026-10-18 Alias added: GHSA-5pvx-6xr7-wr9x
- 2026-10-19 Fix available: Linux/[email protected] · CNA
- 2026-10-20 Affected versions changed · Red Hat
- 2026-10-20 CVSS score added · Red Hat
- 2026-11-06 Affected versions changed · Red Hat
References
Other 8
- https://git.kernel.org/stable/c/0c83a8a45fed256ccc5fe7160b436b671fc79fb8
- https://git.kernel.org/stable/c/aa555ed5ed0d15efbaf27e0e9f152a6df715278a
- https://git.kernel.org/stable/c/32b5f0b338bf59391a1cff9a6190a72c4d2c1ba8
- https://git.kernel.org/stable/c/6fad2c34d451d11a9f3f946cae1105fee91d96b8
- https://git.kernel.org/stable/c/bf41af8f910cbb5d776a1dfa0671d31a7e262e28
- https://git.kernel.org/stable/c/f234197f3bda3aea5d4b1e591d6bcb3660a8b3fc
- https://git.kernel.org/stable/c/0a0412745c86acd089c6460da715ab966b1615e7
- https://git.kernel.org/stable/c/408cff6bd60636df201274d320edfdfde9ed41db
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Sources
- CVE-2026-98577 · CVE Program
- CVE-2026-98577 · NVD
- FIRST EPSS
- GHSA-5pvx-6xr7-wr9x · GitHub Advisory Database · CC BY 4.0
- CVE-2026-98577 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences