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NVD / CVE Program· CNA Linux

CVE-2026-80800: nfc: llcp: bound the connect_sn TLV walk to the skb

Noroxi assessment

Priority: Monitor (action score 0/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.23% (FIRST EPSS).
  • Fixed version: Linux Linux 0cfbdb0e13ab5b0765d77f96af67eb879cbc9736, 1964addc8dd535a05d5d3b55b4d1ac19ae31aa65, 22e5177ba1196a0b272a6a46c2575eb940a939c4.

Low priority for now. Upgrade to Linux Linux 0cfbdb0e13ab5b0765d77f96af67eb879cbc9736, 1964addc8dd535a05d5d3b55b4d1ac19ae31aa65, 22e5177ba1196a0b272a6a46c2575eb940a939c4 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: nfc: llcp: bound the connect_sn TLV walk to the skb Commit 27256cdb290e ("nfc: llcp: bound SNL TLV parsing to the skb and add length checks") fixed the unbounded TLV walk in nfc_llcp_recv_snl(), and commit d8bd2dedbde5 ("nfc: llcp: fix OOB read and u8 offset wrap in TLV parsers") subsequently bounded nfc_llcp_parse_gb_tlv() and nfc_llcp_parse_connection_tlv(). One sibling parser sharing the same pattern remains unbounded: nfc_llcp_connect_sn(). nfc_llcp_connect_sn() walks a TLV list, reading a two-byte header (type, length) followed by length bytes of value, without checking that the two header bytes or the declared length stay within the buffer. It returns a pointer to a service name of up to 255 bytes that may point past the end of the skb; it is subsequently consumed by memcmp() in nfc_llcp_sock_from_sn(). In addition tlv_array_len was computed as "skb->len - LLCP_HEADER_SIZE" in size_t, so a CONNECT/CC frame shorter than the LLCP header underflows to a huge length and the walk runs far past the buffer. nfc_llcp_connect_sn() is reachable from nfc_llcp_recv_connect() and nfc_llcp_recv_cc(), i.e. from received CONNECT and CC PDUs. A nearby NFC device can reach this without authentication; LLCP link activation happens automatically after NFC-DEP, and the nfc_llcp_rx_skb() dispatcher applies no minimum-length guard. Walk the TLV list by pointer, bounded by skb_tail_pointer(skb), and validate each declared length before use, matching the approach already used for nfc_llcp_recv_snl(). Starting the walk at &skb->data[LLCP_HEADER_SIZE] against the tail pointer also removes the size_t underflow for short frames. Found by 0sec automated security-research tooling (https://0sec.ai).

—No exploit Fix available
Published
Sep 4, 2026
Updated
Oct 19, 2026
EPSS
0.2% · 14th percentile
CWE
—

Report tools

JSON

Action score

0

Monitor

Low priority for now.

CVSS
0 / 40 · —
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

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Noroxi analysis

What does it mean in your environment?

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 3.3affected
    • d646960f7986fefb460a2b062d5ccc8ccfeacc3a and later · before b2ebdfe3d5b76e91f267a61cbc3f9a0e3f77071eaffected · git
    • d646960f7986fefb460a2b062d5ccc8ccfeacc3a and later · before e18d044bab6d3d0280639098c3fe6621692cbfe2affected · git
    • d646960f7986fefb460a2b062d5ccc8ccfeacc3a and later · before 65a0ec7783b06068dda6745dd689bf4a91ee64aaaffected · git
    • d646960f7986fefb460a2b062d5ccc8ccfeacc3a and later · before 1964addc8dd535a05d5d3b55b4d1ac19ae31aa65affected · git
    • d646960f7986fefb460a2b062d5ccc8ccfeacc3a and later · before 389986fd79e4d43f971a03b512645a1bb63c982faffected · git
    • d646960f7986fefb460a2b062d5ccc8ccfeacc3a and later · before e87527b506c40db9af528714b7b1240918eb80fcaffected · git
    • d646960f7986fefb460a2b062d5ccc8ccfeacc3a and later · before 22e5177ba1196a0b272a6a46c2575eb940a939c4affected · git
    • d646960f7986fefb460a2b062d5ccc8ccfeacc3a and later · before 0cfbdb0e13ab5b0765d77f96af67eb879cbc9736affected · git
    • d646960f7986fefb460a2b062d5ccc8ccfeacc3a and later · before 55c68ac93e7dacc0f5f608b9c39dd4ff48cf28e8affected · git

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.187-16.1.187-1
Debian:12linux-6.12before 6.12.107-1~deb12u16.12.107-1~deb12u1
Debian:13linuxbefore 6.12.107-16.12.107-1
Debian:14linuxbefore 7.1.12-17.1.12-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation
    40Plan
  • CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment
    40Plan
  • CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2026-80798Sep 4, 2026 · nfc: llcp: reject PDUs shorter than the LLCP header
    0Monitor
  • ← EarlierCVE-2026-80799Sep 4, 2026 · nfc: llcp: fix OOB read and u8 offset wrap in TLV parsers
    0Monitor
  • Later →CVE-2026-80801Sep 4, 2026 · nfc: microread: validate target discovery payload lengths
    0Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux0cfbdb0e13ab5b0765d77f96af67eb879cbc9736Vendor (CNA)
Linux Linux1964addc8dd535a05d5d3b55b4d1ac19ae31aa65Vendor (CNA)
Linux Linux22e5177ba1196a0b272a6a46c2575eb940a939c4Vendor (CNA)
Linux Linux389986fd79e4d43f971a03b512645a1bb63c982fVendor (CNA)
Linux Linux55c68ac93e7dacc0f5f608b9c39dd4ff48cf28e8Vendor (CNA)
Linux Linux65a0ec7783b06068dda6745dd689bf4a91ee64aaVendor (CNA)
Linux Linuxb2ebdfe3d5b76e91f267a61cbc3f9a0e3f77071eVendor (CNA)
Linux Linuxe18d044bab6d3d0280639098c3fe6621692cbfe2Vendor (CNA)
Linux Linuxe87527b506c40db9af528714b7b1240918eb80fcVendor (CNA)
azl3 kernel 6.6.150.1-1 on Azure Linux 3.0—Microsoft (MSRC)
debian:linux6.1.187-1 · Debian:12Package registry (OSV)
debian:linux-6.126.12.107-1~deb12u1 · Debian:12Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

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Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

No CVSS vector for this record, so attack conditions can't be derived.

Weakness class (CWE)

—

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

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References

Show all references (8 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

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