{ "schemaVersion": 1, "attribution": [ { "source": "CISA Known Exploited Vulnerabilities", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog", "licence": "US government work" }, { "source": "GitHub Advisory Database", "url": "https://github.com/advisories", "licence": "CC BY 4.0" }, { "source": "Have I Been Pwned", "url": "https://haveibeenpwned.com/", "licence": "CC BY 4.0" }, { "source": "CVE Program (CVE records)", "url": "https://www.cve.org/Legal/TermsOfUse", "licence": "CVE Terms of Use", "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.", "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy." }, { "source": "FIRST EPSS", "url": "https://www.first.org/epss/", "licence": "free to use; FIRST requests attribution" } ], "record": { "id": "CVE-2026-52942", "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-52942", "idYear": 2026, "status": "PUBLISHED", "publishedAt": "2026-06-24T07:14:30.610Z", "updatedAt": "2026-10-19T19:47:08.584Z", "importedAt": "2026-10-24T01:58:14.884Z", "snapshot": { "id": "cve_2026-10-24_midnight_baseline", "at": "2026-10-24T00:00:00.000Z", "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z" }, "facts": { "title": "netfilter: nf_log: validate MAC header was set before dumping it", "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_log: validate MAC header was set before dumping it\n\nThe fallback path of dump_mac_header() guards the MAC header access\nonly with \"skb->mac_header != skb->network_header\", without checking\nskb_mac_header_was_set(). When the MAC header is unset, mac_header is\n0xffff, so the test passes and skb_mac_header(skb) returns\nskb->head + 0xffff, ~64 KiB past the buffer; the loop then reads\ndev->hard_header_len bytes out of bounds into the kernel log.\n\nThis is reachable via the netdev logger: nf_log_unknown_packet() calls\ndump_mac_header() unconditionally, and an skb sent through AF_PACKET\nwith PACKET_QDISC_BYPASS reaches the egress hook with mac_header still\nunset (__dev_queue_xmit(), which would reset it, is bypassed).\n\nAdd the skb_mac_header_was_set() check the ARPHRD_ETHER path already\nuses, and replace the open-coded MAC header length test with\nskb_mac_header_len(). Only skbs with an unset MAC header are affected;\nvalid ones are dumped as before.\n\n BUG: KASAN: slab-out-of-bounds in dump_mac_header (net/netfilter/nf_log_syslog.c:831)\n Read of size 1 at addr ffff88800ea49d3f by task exploit/148\n Call Trace:\n kasan_report (mm/kasan/report.c:595)\n dump_mac_header (net/netfilter/nf_log_syslog.c:831)\n nf_log_netdev_packet (net/netfilter/nf_log_syslog.c:938 net/netfilter/nf_log_syslog.c:963)\n nf_log_packet (net/netfilter/nf_log.c:260)\n nft_log_eval (net/netfilter/nft_log.c:60)\n nft_do_chain (net/netfilter/nf_tables_core.c:285)\n nft_do_chain_netdev (net/netfilter/nft_chain_filter.c:307)\n nf_hook_slow (net/netfilter/core.c:619)\n nf_hook_direct_egress (net/packet/af_packet.c:257)\n packet_xmit (net/packet/af_packet.c:280)\n packet_sendmsg (net/packet/af_packet.c:3114)\n __sys_sendto (net/socket.c:2265)", "affected": [ { "vendor": "Linux", "product": "Linux", "defaultStatus": "unaffected", "versions": [ { "version": "7eb9282cd0efac08b8377cbd5037ba297c77e3f7", "status": "affected", "versionType": "git", "lessThan": "2e96e1bc9b4d5450e6c33f078e19a9bc1dda6c0b" }, { "version": "7eb9282cd0efac08b8377cbd5037ba297c77e3f7", "status": "affected", "versionType": "git", "lessThan": "d704ee9c7bc68a161684c51a7ac05b446dcf38d4" }, { "version": "7eb9282cd0efac08b8377cbd5037ba297c77e3f7", "status": "affected", "versionType": "git", "lessThan": "befb8968a2abdfa948d5600ea7f7a509a292a590" }, { "version": "7eb9282cd0efac08b8377cbd5037ba297c77e3f7", "status": "affected", "versionType": "git", "lessThan": "8a81e336da685423f5b64aac4d571e63d674c52a" }, { "version": "7eb9282cd0efac08b8377cbd5037ba297c77e3f7", "status": "affected", "versionType": "git", "lessThan": "c38d41134085193efd5b237cf513ad5b3421a60d" }, { "version": "7eb9282cd0efac08b8377cbd5037ba297c77e3f7", "status": "affected", "versionType": "git", "lessThan": "af1b7699466f6556b351fa25d3dc870abfb5d310" }, { "version": "7eb9282cd0efac08b8377cbd5037ba297c77e3f7", "status": "affected", "versionType": "git", "lessThan": "65ef7397eb9a296e91839f5fd10be96f23d332e7" }, { "version": "7eb9282cd0efac08b8377cbd5037ba297c77e3f7", "status": "affected", "versionType": "git", "lessThan": "a84b6fedbc97078788be78dbdd7517d143ad1a77" } ] }, { "vendor": "Linux", "product": "Linux", "defaultStatus": "affected", "versions": [ { "version": "2.6.36", "status": "affected" }, { "version": "0", "status": "unaffected", "versionType": "semver", "lessThan": "2.6.36" }, { "version": "5.10.261", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.10.*" }, { "version": "5.15.210", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.15.*" }, { "version": "6.1.176", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.1.*" }, { "version": "6.6.143", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.6.*" }, { "version": "6.12.94", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.12.*" }, { "version": "6.18.36", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.18.*" }, { "version": "7.0.13", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "7.0.*" }, { "version": "7.1", "status": "unaffected", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*" } ] } ] } } }