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VulnerabilityPublished Updated

CVE-2026-80799: Linux kernel · nfc: llcp: fix OOB read and u8 offset wrap in TLV parsers

Affects Linux kernelSource GCVE Database

0

Not known to be exploited.

Data as of 26 Oct 2026, 15:59 UTC

Severity
Medium

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS
0.2% chance of exploitation in 30 days – higher than 14% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 4 Sep 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Affected software

ProductAffectedFixed in
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threatsAffected
  • 6.17.0-5.5 – 7.0.0-34.34
22 affected builds		Fixed in–
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threatsAffected
  • 6.17.0-1002.2 – 7.0.0-1013.13
14 affected builds		Fixed in–
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threatsAffected
  • 6.17.0-1003.3 – 7.0.0-1014.14
14 affected builds		Fixed in–
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threatsAffected
  • 7.0.0-1003.3 – 7.0.0-1013.13
8 affected builds		Fixed in–
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threatsAffected
  • 6.17.0-1002.2 – 7.0.0-1013.13
12 affected builds		Fixed in–
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther threatsAffected
  • 7.0.0-1002.3 – 7.0.0-1007.8
5 affected builds		Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A fix is available that addresses all three issues by widening the offset variable from 8-bit to 16-bit and adding proper bounds checks before accessing TLV fields. Users should apply the official Linux kernel patches that resolve CVE-2026-80799. Since this is a kernel vulnerability, updating to a patched kernel version is the recommended remediation. Patch status is not explicitly confirmed in the provided data; check the vendor advisory or Linux kernel mailing lists for the official patch and update guidance.

Description

In the Linux kernel, the following vulnerability has been resolved: nfc: llcp: fix OOB read and u8 offset wrap in TLV parsers nfc_llcp_parse_gb_tlv() and nfc_llcp_parse_connection_tlv() contain three related bugs in their TLV parsing loops: 1. 'offset' is declared u8 but tlv_array_len is u16. When TLV data advances offset past 255 it silently wraps to zero, causing infinite loops or double-processing of buffer data. 2. Before reading tlv[0] (type) and tlv[1] (length) there is no check that offset+2 <= tlv_array_len. A truncated TLV causes an OOB read of one byte past the buffer end. 3. After reading the length field, the value bytes are accessed without checking offset+2+length <= tlv_array_len. A crafted length=0xFF on a short buffer causes up to 255 bytes of OOB read past the buffer end. Both functions are reachable without authentication via nfc_llcp_set_remote_gb() which feeds remote LLCP general bytes directly into nfc_llcp_parse_gb_tlv() with no additional validation. Fix all three issues by widening offset from u8 to u16 and adding bounds checks for both the TLV header and value field before each access.

References

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