{
  "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"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:14",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "7.2.9-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "details": "In the Linux kernel, the following vulnerability has been resolved:  vlan: require the MAC header to be present in __vlan_insert_inner_tag()  __vlan_insert_inner_tag() only guarantees head room via skb_cow_head(), never that mac_len bytes of MAC header are present.  Its ETH_HLEN wrappers - __vlan_insert_tag() under skb_vlan_push(), and vlan_insert_tag() under validate_xmit_vlan() on the generic transmit path - therefore rewrite the first 16 bytes at skb-\u003edata: a 12-byte memmove plus two 2-byte stores at +12 and +14.  No caller supplies the bound, while the pop helpers use skb_ensure_writable()/pskb_may_pull().  An IFF_TUN device has hard_header_len == 0, so packet_snd() accepts a one-byte AF_PACKET/SOCK_RAW frame.  The first vlan push only sets a hwaccel tag; the next - clsact \"action vlan push\" or bpf_skb_vlan_push() - enters the helper with skb-\u003elen still 1.  The head comes from skbuff_small_head without __GFP_ZERO, so each push drags bytes from beyond skb-\u003etail into the frame.  After three the one-byte send leaves as 13 bytes carrying 11 bytes of uninitialised slab:    0000: 5a b3 62 12 80 88 ff ff 00 b3 62 12 81            `------------------------------'   only 0x5a was sent; the rest is slab, here the top 56 bits of a   linear-map address  Require the MAC header the helper rewrites to be present, so such a frame is dropped rather than transmitted.",
  "id": "DEBIAN-CVE-2026-98377",
  "modified": "2026-10-10T04:47:27.440886209Z",
  "published": "2026-10-09T08:16:56.010Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://security-tracker.debian.org/tracker/CVE-2026-98377"
    }
  ],
  "upstream": [
    "CVE-2026-98377"
  ]
}