CVE-2026-80800: linux
Vulnerability summary
CVE-2026-80800 is a vulnerability in linux with no CVSS score yet. EPSS estimates a 0.23% chance of exploitation in the next 30 days, higher than 13.4% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 3 · Related 2Timeline
- 04-09-2026PublishedVulnerability first disclosed.
- 19-10-2026Last modifiedVulnerability information updated.
Description
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).
CVSS metrics
Risk metrics not yet published.
EPSS trend
Probability
0.23%
Chance of exploitation in the next 30 days
Percentile
13%
Versus all other CVEs
30-day change
0.00 pp
From 0.23% on 21-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeNo weakness data has been published for this record.
Affected systems
Ubuntu169 products
- linuxAll versions (No fix recorded)
- linux-allwinner-5.19All versions (No fix recorded)
- linux-awsAll versions (No fix recorded)
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Debian2 products
- linux< 6.1.187-1 | < 6.12.107-1 | < 7.1.12-1
- linux-6.12< 6.12.107-1~deb12u1
Linux1 product
- linux≥ d646960f7986fefb460a2b062d5ccc8ccfeacc3a, < b2ebdfe3d5b76e91f267a61cbc3f9a0e3f77071e | ≥ d646960f7986fefb460a2b062d5ccc8ccfeacc3a, < e18d044bab6d3d0280639098c3fe6621692cbfe2 | ≥ d646960f7986fefb460a2b062d5ccc8ccfeacc3a, < 65a0ec7783b06068dda6745dd689bf4a91ee64aa | ≥ d646960f7986fefb460a2b062d5ccc8ccfeacc3a, < 1964addc8dd535a05d5d3b55b4d1ac19ae31aa65 | ≥ d646960f7986fefb460a2b062d5ccc8ccfeacc3a, < 389986fd79e4d43f971a03b512645a1bb63c982f | ≥ d646960f7986fefb460a2b062d5ccc8ccfeacc3a, < e87527b506c40db9af528714b7b1240918eb80fc | ≥ d646960f7986fefb460a2b062d5ccc8ccfeacc3a, < 22e5177ba1196a0b272a6a46c2575eb940a939c4 | ≥ d646960f7986fefb460a2b062d5ccc8ccfeacc3a, < 0cfbdb0e13ab5b0765d77f96af67eb879cbc9736 | ≥ d646960f7986fefb460a2b062d5ccc8ccfeacc3a, < 55c68ac93e7dacc0f5f608b9c39dd4ff48cf28e8 | 3.3
3 vendors · 172 products
