Answer in brief
CVE-2026-52942 records a High severity (CVSS 7.1) vulnerability in netfilter: nf_log: validate MAC header was set before dumping it. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
Answer in brief
CVE-2026-52942 records a High severity (CVSS 7.1) vulnerability in netfilter: nf_log: validate MAC header was set before dumping it. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.1. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=7eb9282cd0efac08b8377cbd5037ba297c77e3f7 <2e96e1bc9b4d5450e6c33f078e19a9bc1dda6c0b || >=7eb9282cd0efac08b8377cbd5037ba297c77e3f7 <d704ee9c7bc68a161684c51a7ac05b446dcf38d4 || >=7eb9282cd0efac08b8377cbd5037ba297c77e3f7 <befb8968a2abdfa948d5600ea7f7a509a292a590 || >=7eb9282cd0efac08b8377cbd5037ba297c77e3f7 <8a81e336da685423f5b64aac4d571e63d674c52a || >=7eb9282cd0efac08b8377cbd5037ba297c77e3f7 <c38d41134085193efd5b237cf513ad5b3421a60d || >=7eb9282cd0efac08b8377cbd5037ba297c77e3f7 <af1b7699466f6556b351fa25d3dc870abfb5d310 || >=7eb9282cd0efac08b8377cbd5037ba297c77e3f7 <65ef7397eb9a296e91839f5fd10be96f23d332e7 || >=7eb9282cd0efac08b8377cbd5037ba297c77e3f7 <a84b6fedbc97078788be78dbdd7517d143ad1a77 | 2e96e1bc9b4d5450e6c33f078e19a9bc1dda6c0b, d704ee9c7bc68a161684c51a7ac05b446dcf38d4, befb8968a2abdfa948d5600ea7f7a509a292a590, 8a81e336da685423f5b64aac4d571e63d674c52a, c38d41134085193efd5b237cf513ad5b3421a60d, af1b7699466f6556b351fa25d3dc870abfb5d310, 65ef7397eb9a296e91839f5fd10be96f23d332e7, a84b6fedbc97078788be78dbdd7517d143ad1a77 |
| Linux/Linuxgeneric | 2.6.36 | Not reported |
Published upstream
Jun 24, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jun 24, 2026
In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_log: validate MAC header was set before dumping it The fallback path of dump_mac_header() guards the MAC header access only with "skb->mac_header != skb->network_header", without checking skb_mac_header_was_set(). When the MAC header is unset, mac_header is 0xffff, so the test passes and skb_mac_header(skb) returns skb->head + 0xffff, ~64 KiB past the buffer; the loop then reads dev->hard_header_len bytes out of bounds into the kernel log. This is reachable via the netdev logger: nf_log_unknown_packet() calls dump_mac_header() unconditionally, and an skb sent through AF_PACKET with PACKET_QDISC_BYPASS reaches the egress hook with mac_header still unset (__dev_queue_xmit(), which would reset it, is bypassed). Add the skb_mac_header_was_set() check the ARPHRD_ETHER path already uses, and replace the open-coded MAC header length test with skb_mac_header_len(). Only skbs with an unset MAC header are affected; valid ones are dumped as before. BUG: KASAN: slab-out-of-bounds in dump_mac_header (net/netfilter/nf_log_syslog.c:831) Read of size 1 at addr ffff88800ea49d3f by task exploit/148 Call Trace: kasan_report (mm/kasan/report.c:595) dump_mac_header (net/netfilter/nf_log_syslog.c:831) nf_log_netdev_packet (net/netfilter/nf_log_syslog.c:938 net/netfilter/nf_log_syslog.c:963) nf_log_packet (net/netfilter/nf_log.c:260) nft_log_eval (net/netfilter/nft_log.c:60) nft_do_chain (net/netfilter/nf_tables_core.c:285) nft_do_chain_netdev (net/netfilter/nft_chain_filter.c:307) nf_hook_slow (net/netfilter/core.c:619) nf_hook_direct_egress (net/packet/af_packet.c:257) packet_xmit (net/packet/af_packet.c:280) packet_sendmsg (net/packet/af_packet.c:3114) __sys_sendto (net/socket.c:2265)
Quoted source text, attributed separately from HOL analysis.
CVSS is 7.1. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=7eb9282cd0efac08b8377cbd5037ba297c77e3f7 <2e96e1bc9b4d5450e6c33f078e19a9bc1dda6c0b || >=7eb9282cd0efac08b8377cbd5037ba297c77e3f7 <d704ee9c7bc68a161684c51a7ac05b446dcf38d4 || >=7eb9282cd0efac08b8377cbd5037ba297c77e3f7 <befb8968a2abdfa948d5600ea7f7a509a292a590 || >=7eb9282cd0efac08b8377cbd5037ba297c77e3f7 <8a81e336da685423f5b64aac4d571e63d674c52a || >=7eb9282cd0efac08b8377cbd5037ba297c77e3f7 <c38d41134085193efd5b237cf513ad5b3421a60d || >=7eb9282cd0efac08b8377cbd5037ba297c77e3f7 <af1b7699466f6556b351fa25d3dc870abfb5d310 || >=7eb9282cd0efac08b8377cbd5037ba297c77e3f7 <65ef7397eb9a296e91839f5fd10be96f23d332e7 || >=7eb9282cd0efac08b8377cbd5037ba297c77e3f7 <a84b6fedbc97078788be78dbdd7517d143ad1a77 | 2e96e1bc9b4d5450e6c33f078e19a9bc1dda6c0b, d704ee9c7bc68a161684c51a7ac05b446dcf38d4, befb8968a2abdfa948d5600ea7f7a509a292a590, 8a81e336da685423f5b64aac4d571e63d674c52a, c38d41134085193efd5b237cf513ad5b3421a60d, af1b7699466f6556b351fa25d3dc870abfb5d310, 65ef7397eb9a296e91839f5fd10be96f23d332e7, a84b6fedbc97078788be78dbdd7517d143ad1a77 |
| Linux/Linuxgeneric | 2.6.36 | Not reported |
Published upstream
Jun 24, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jun 24, 2026
In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_log: validate MAC header was set before dumping it The fallback path of dump_mac_header() guards the MAC header access only with "skb->mac_header != skb->network_header", without checking skb_mac_header_was_set(). When the MAC header is unset, mac_header is 0xffff, so the test passes and skb_mac_header(skb) returns skb->head + 0xffff, ~64 KiB past the buffer; the loop then reads dev->hard_header_len bytes out of bounds into the kernel log. This is reachable via the netdev logger: nf_log_unknown_packet() calls dump_mac_header() unconditionally, and an skb sent through AF_PACKET with PACKET_QDISC_BYPASS reaches the egress hook with mac_header still unset (__dev_queue_xmit(), which would reset it, is bypassed). Add the skb_mac_header_was_set() check the ARPHRD_ETHER path already uses, and replace the open-coded MAC header length test with skb_mac_header_len(). Only skbs with an unset MAC header are affected; valid ones are dumped as before. BUG: KASAN: slab-out-of-bounds in dump_mac_header (net/netfilter/nf_log_syslog.c:831) Read of size 1 at addr ffff88800ea49d3f by task exploit/148 Call Trace: kasan_report (mm/kasan/report.c:595) dump_mac_header (net/netfilter/nf_log_syslog.c:831) nf_log_netdev_packet (net/netfilter/nf_log_syslog.c:938 net/netfilter/nf_log_syslog.c:963) nf_log_packet (net/netfilter/nf_log.c:260) nft_log_eval (net/netfilter/nft_log.c:60) nft_do_chain (net/netfilter/nf_tables_core.c:285) nft_do_chain_netdev (net/netfilter/nft_chain_filter.c:307) nf_hook_slow (net/netfilter/core.c:619) nf_hook_direct_egress (net/packet/af_packet.c:257) packet_xmit (net/packet/af_packet.c:280) packet_sendmsg (net/packet/af_packet.c:3114) __sys_sendto (net/socket.c:2265)
Quoted source text, attributed separately from HOL analysis.