{"apiVersion":"1.0","identifier":"CVE-2026-74569","description":"In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_conntrack_sip: widen NAT rewrite delta to s32 in sip_help_tcp() sip_help_tcp() stores the size change of each NAT-rewritten SIP message in s16 diff and accumulates it in s16 tdiff, but a single message can grow by more than S16_MAX while the packet stays under the 65535 enlarge_skb() limit: nf_nat_sip() rewrites every matching URI, and a long Contact list expands the message by tens of kilobytes. diff then wraps, and -datalen = datalen + diff - msglen- yields a huge unsigned datalen, so the next iteration-s ct_sip_get_header() reads past the linearized skb tail. Widen diff, tdiff and the seq_adjust hook to s32. Both are bounded by the 65535 byte packet limit, and the seqadj core is already s32 (nf_ct_seqadj_set() takes s32), so no previously accepted input is rejected. BUG: KASAN: use-after-free in ct_sip_get_header (net/netfilter/nf_conntrack_sip.c:464) Read of size 1 at addr ffff888010800000 by task ksoftirqd/1/25 ct_sip_get_header (net/netfilter/nf_conntrack_sip.c:464) sip_help_tcp (net/netfilter/nf_conntrack_sip.c:1694) nf_confirm (net/netfilter/nf_conntrack_proto.c:183) nf_hook_slow (net/netfilter/core.c:619) ip6_output (net/ipv6/ip6_output.c:246) ip6_forward (net/ipv6/ip6_output.c:690) ipv6_rcv (net/ipv6/ip6_input.c:351) __netif_receive_skb_one_core (net/core/dev.c:6212) process_backlog (net/core/dev.c:6676) __napi_poll (net/core/dev.c:7735) net_rx_action (net/core/dev.c:7955) handle_softirqs (kernel/softirq.c:622) run_ksoftirqd (kernel/softirq.c:1076) ...","publishedAt":"2026-08-15T13:18:02","lastModifiedAt":"2026-08-19T17:21:11","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-74569","cvssScore":9.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","epssProbability":0.00388,"riskScore":1.01,"affectedProduct":"Linux kernel","affectedVersions":"unknown","vulnerabilityType":"Kernel","operatingSystems":[],"links":{"self":"https://www.redsauce.net/api/cves/CVE-2026-74569","webPages":{"es":"https://www.redsauce.net/es/cves/CVE-2026-74569","en":"https://www.redsauce.net/en/cves/CVE-2026-74569","fr":"https://www.redsauce.net/fr/cves/CVE-2026-74569","pt":"https://www.redsauce.net/pt/cves/CVE-2026-74569","de":"https://www.redsauce.net/de/cves/CVE-2026-74569","sk":"https://www.redsauce.net/sk/cves/CVE-2026-74569","el":"https://www.redsauce.net/el/cves/CVE-2026-74569"},"source":"https://nvd.nist.gov/vuln/detail/CVE-2026-74569"}}