{"id":"CVE-2026-74569","revision":"b2de435849514fcd93a4bb140e622897","records":[{"revision":"b2de435849514fcd93a4bb140e622897","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-74569","aliases":[],"title":"netfilter: nf_conntrack_sip: widen NAT rewrite delta to s32 in sip_help_tcp()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_conntrack_sip: widen NAT rewrite delta to s32 in sip_help_tcp()\n\nsip_help_tcp() stores the size change of each NAT-rewritten SIP message\nin s16 diff and accumulates it in s16 tdiff, but a single message can\ngrow by more than S16_MAX while the packet stays under the 65535\nenlarge_skb() limit: nf_nat_sip() rewrites every matching URI, and a long\nContact list expands the message by tens of kilobytes. diff then wraps,\nand \"datalen = datalen + diff - msglen\" yields a huge unsigned datalen,\nso the next iteration's ct_sip_get_header() reads past the linearized skb\ntail.\n\nWiden diff, tdiff and the seq_adjust hook to s32. Both are bounded by the\n65535 byte packet limit, and the seqadj core is already s32\n(nf_ct_seqadj_set() takes s32), so no previously accepted input is\nrejected.\n\n  BUG: KASAN: use-after-free in ct_sip_get_header (net/netfilter/nf_conntrack_sip.c:464)\n  Read of size 1 at addr ffff888010800000 by task ksoftirqd/1/25\n   ct_sip_get_header (net/netfilter/nf_conntrack_sip.c:464)\n   sip_help_tcp (net/netfilter/nf_conntrack_sip.c:1694)\n   nf_confirm (net/netfilter/nf_conntrack_proto.c:183)\n   nf_hook_slow (net/netfilter/core.c:619)\n   ip6_output (net/ipv6/ip6_output.c:246)\n   ip6_forward (net/ipv6/ip6_output.c:690)\n   ipv6_rcv (net/ipv6/ip6_input.c:351)\n   __netif_receive_skb_one_core (net/core/dev.c:6212)\n   process_backlog (net/core/dev.c:6676)\n   __napi_poll (net/core/dev.c:7735)\n   net_rx_action (net/core/dev.c:7955)\n   handle_softirqs (kernel/softirq.c:622)\n   run_ksoftirqd (kernel/softirq.c:1076)\n   ...","state":0,"publishedAt":"2026-08-15T12:28:09.476+00:00","modifiedAt":"2026-10-16T19:05:56.675+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"include/linux/netfilter/nf_conntrack_sip.h\",\n                        \"net/netfilter/nf_conntrack_sip.c\",\n                        \"net/netfilter/nf_nat_sip.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"f5b321bd37fbec9188feb1f721ab46a5ac0b35da\",\n                            \"lessThan\": \"ed1f9be6dc8e2e280b8725e44ccdc6e0cd38640d\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"f5b321bd37fbec9188feb1f721ab46a5ac0b35da\",\n                            \"lessThan\": \"1b0843f9e9b9b0b9b4b70d143b67e58163c85b2c\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"f5b321bd37fbec9188feb1f721ab46a5ac0b35da\",\n                            \"lessThan\": \"32d4abc8923b0d4046fd63ad6e4917872e44eb6d\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"f5b321bd37fbec9188feb1f721ab46a5ac0b35da\",\n                            \"lessThan\": \"63eea41759fd682229c14e0a2205802b46d106f3\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"f5b321bd37fbec9188feb1f721ab46a5ac0b35da\",\n                            \"lessThan\": \"c97621a110e386b2dd69e276eb699e1d3cec581d\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"f5b321bd37fbec9188feb1f721ab46a5ac0b35da\",\n                            \"lessThan\": \"f74554e67ccf04d1fa71069e8c9afa2717e40716\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"f5b321bd37fbec9188feb1f721ab46a5ac0b35da\",\n                            \"lessThan\": \"ef5e2c6555d2bb52dfe0e4053a8c6193f9d83b64\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"f5b321bd37fbec9188feb1f721ab46a5ac0b35da\",\n                            \"lessThan\": \"db3d0e0e5d4bc5ab4fe445b9f413d1b486508ca5\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"include/linux/netfilter/nf_conntrack_sip.h\",\n                        \"net/netfilter/nf_conntrack_sip.c\",\n                        \"net/netfilter/nf_nat_sip.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"2.6.34\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"2.6.34\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.10.265\",\n                            \"lessThanOrEqual\": \"5.10.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.15.216\",\n                            \"lessThanOrEqual\": \"5.15.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.183\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.151\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.103\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.44\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.1.8\",\n                            \"lessThanOrEqual\": \"7.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","score":9.8,"severity":"CRITICAL"}],"references":["https://git.kernel.org/stable/c/ed1f9be6dc8e2e280b8725e44ccdc6e0cd38640d","https://git.kernel.org/stable/c/1b0843f9e9b9b0b9b4b70d143b67e58163c85b2c","https://git.kernel.org/stable/c/32d4abc8923b0d4046fd63ad6e4917872e44eb6d","https://git.kernel.org/stable/c/63eea41759fd682229c14e0a2205802b46d106f3","https://git.kernel.org/stable/c/c97621a110e386b2dd69e276eb699e1d3cec581d","https://git.kernel.org/stable/c/f74554e67ccf04d1fa71069e8c9afa2717e40716","https://git.kernel.org/stable/c/ef5e2c6555d2bb52dfe0e4053a8c6193f9d83b64","https://git.kernel.org/stable/c/db3d0e0e5d4bc5ab4fe445b9f413d1b486508ca5"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-74569","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-74569","identifiers":["CVE-2026-74569"]},"retained":false,"historicalAffected":[]}],"coverage":[]}