Uninitialized memory read in Linux kernel NFC LLCP HDLC handling
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
Linux kernel NFC LLCP code from 3.3 before the fixed releases listed below is affected. The function nfc_llcp_recv_hdlc() reads the sequence byte of a two-byte I, RR or RNR PDU before checking the frame length, so the read touches one byte of uninitialized memory. That byte becomes the N(R) or N(S) value, and the fix drops truncated PDUs without a DM reply.
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: drop truncated I/RR/RNR PDUs in nfc_llcp_recv_hdlc() nfc_llcp_recv_hdlc() reads the sequence byte skb->data[2], via nfc_llcp_ns()/nfc_llcp_nr(), before any length check. The receive path only guarantees the two-byte LLCP header -- __nfc_llcp_recv() checks it with pskb_may_pull() and nfc_llcp_recv_agf() admits two-byte inner PDUs -- so a two-byte I, RR or RNR PDU reads one byte of uninitialised skb tailroom. The byte becomes N(R)/N(S); a peer can already set those with a well-formed PDU, so this is acting on uninitialised memory, not new peer control. Guard the read with pskb_may_pull(), as commit 95674f506c63 ("nfc: llcp: reject PDUs shorter than the LLCP header") did for the two-byte header, so the sequence byte is present and linear before it is read. RR and RNR PDUs are LLCP_HEADER_SIZE + LLCP_SEQUENCE_SIZE bytes and an I PDU is longer, so no valid frame is rejected; a truncated PDU is malformed, so return without a DM reply.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
Remediation
Upgrade the Linux kernel to 5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.112, 6.18.55, 7.2.9 or 7.3, depending on the release branch in use.
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-2026-98482
- 2026-10-18 Alias added: GHSA-8vvq-jjhc-wfc4
- 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/3afdbebfee2ef7e9510880868cfb482cbffe6836
- https://git.kernel.org/stable/c/9b4086eb67a9a3b1ce69fef1b6793827363703ce
- https://git.kernel.org/stable/c/51b6d73373589abb9de4d84767b0db1bc8d395d9
- https://git.kernel.org/stable/c/066205553a0106565bcede934f5721c25ebd6e4e
- https://git.kernel.org/stable/c/18f60ee882403d5b48097f5f6ae45f794e4cc643
- https://git.kernel.org/stable/c/810f204ef8f61f0c930cf6b3280050b3ee6a8ae7
- https://git.kernel.org/stable/c/744e61bd06188d8bb068c26a461c252f242b05c9
- https://git.kernel.org/stable/c/273f9d667cde649f8de9d72b1303cc2f4b658c50
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Sources
- CVE-2026-98482 · CVE Program
- CVE-2026-98482 · NVD
- FIRST EPSS
- GHSA-8vvq-jjhc-wfc4 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-98482 · 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