{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "f5b321bd37fbec9188feb1f721ab46a5ac0b35da"
            },
            {
              "fixed": "ed1f9be6dc8e2e280b8725e44ccdc6e0cd38640d"
            },
            {
              "fixed": "1b0843f9e9b9b0b9b4b70d143b67e58163c85b2c"
            },
            {
              "fixed": "32d4abc8923b0d4046fd63ad6e4917872e44eb6d"
            },
            {
              "fixed": "63eea41759fd682229c14e0a2205802b46d106f3"
            },
            {
              "fixed": "c97621a110e386b2dd69e276eb699e1d3cec581d"
            },
            {
              "fixed": "f74554e67ccf04d1fa71069e8c9afa2717e40716"
            },
            {
              "fixed": "ef5e2c6555d2bb52dfe0e4053a8c6193f9d83b64"
            },
            {
              "fixed": "db3d0e0e5d4bc5ab4fe445b9f413d1b486508ca5"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.6.34"
            },
            {
              "fixed": "5.10.265"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.11.0"
            },
            {
              "fixed": "5.15.216"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.16.0"
            },
            {
              "fixed": "6.1.183"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.2.0"
            },
            {
              "fixed": "6.6.151"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.103"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.44"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.1.8"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74569.json"
  },
  "details": "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   ...",
  "id": "CVE-2026-74569",
  "modified": "2026-08-21T03:30:23.637363593Z",
  "published": "2026-08-15T12:28:09.476Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/1b0843f9e9b9b0b9b4b70d143b67e58163c85b2c"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/32d4abc8923b0d4046fd63ad6e4917872e44eb6d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/63eea41759fd682229c14e0a2205802b46d106f3"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c97621a110e386b2dd69e276eb699e1d3cec581d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/db3d0e0e5d4bc5ab4fe445b9f413d1b486508ca5"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ed1f9be6dc8e2e280b8725e44ccdc6e0cd38640d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ef5e2c6555d2bb52dfe0e4053a8c6193f9d83b64"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f74554e67ccf04d1fa71069e8c9afa2717e40716"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74569.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-74569"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "netfilter: nf_conntrack_sip: widen NAT rewrite delta to s32 in sip_help_tcp()"
}