{
  "affected": [
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:12",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:13",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.12.113-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:14",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "7.2.11-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "details": "In the Linux kernel, the following vulnerability has been resolved:  net: openvswitch: validate transport header presence in set_ipv6_addr  When executing IPv6 address rewrite actions on IPv6 fragments, set_ipv6_addr() calls update_ipv6_checksum(). If parse_ipv6hdr() processes a non-first IPv6 fragment, it sets key-\u003eip.proto to NEXTHDR_FRAGMENT and returns early without calling skb_set_transport_header().  update_ipv6_checksum() unconditionally evaluates skb_transport_offset() on entry before checking l4_proto.  Because skb-\u003etransport_header is uninitialized, this triggers a warning under CONFIG_DEBUG_NET=y although it is completely harmless.  Fix this by returning early in update_ipv6_checksum() if l4_proto is NEXTHDR_FRAGMENT. This avoids reading the uninitialized transport offset for fragments while preserving the debug warning for any other protocol where the transport header is unexpectedly missing.  See the syzbot trace:  !skb_transport_header_was_set(skb) WARNING: ./include/linux/skbuff.h:3075 at skb_transport_header include/linux/skbuff.h:3075 [inline], CPU#1: syz-executor463/5635 WARNING: ./include/linux/skbuff.h:3075 at skb_transport_offset include/linux/skbuff.h:3250 [inline], CPU#1: syz-executor463/5635 WARNING: ./include/linux/skbuff.h:3075 at update_ipv6_checksum net/openvswitch/actions.c:361 [inline], CPU#1: syz-executor463/5635 WARNING: ./include/linux/skbuff.h:3075 at set_ipv6_addr+0x462/0x660 net/openvswitch/actions.c:399, CPU#1: syz-executor463/5635 [...] RIP: 0010:skb_transport_header include/linux/skbuff.h:3075 [inline] RIP: 0010:skb_transport_offset include/linux/skbuff.h:3250 [inline] RIP: 0010:update_ipv6_checksum net/openvswitch/actions.c:361 [inline] RIP: 0010:set_ipv6_addr+0x462/0x660 net/openvswitch/actions.c:399 [...] Call Trace:  \u003cTASK\u003e  set_ipv6 net/openvswitch/actions.c:531 [inline]  do_execute_actions+0x557e/0x8600 net/openvswitch/actions.c:1366  ovs_execute_actions+0xde/0x520 net/openvswitch/actions.c:1592  ovs_packet_cmd_execute+0xb4f/0xf10 net/openvswitch/datapath.c:705  genl_family_rcv_msg_doit+0x233/0x340 net/netlink/genetlink.c:1114  genl_rcv_msg+0x614/0x7a0 net/netlink/genetlink.c:1209  netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2572  genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218  netlink_unicast+0x7bd/0x940 net/netlink/af_netlink.c:1361  netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1916  sock_sendmsg_nosec+0x14e/0x190 net/socket.c:800",
  "id": "DEBIAN-CVE-2026-99088",
  "modified": "2026-10-27T04:47:39.905982689Z",
  "published": "2026-10-26T15:16:47.517Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://security-tracker.debian.org/tracker/CVE-2026-99088"
    }
  ],
  "upstream": [
    "CVE-2026-99088"
  ]
}