{
  "cveId": "CVE-2026-98570",
  "url": "https://patchblox.com/security/cve/CVE-2026-98570",
  "summary": "CVE-2026-98570 is fixed in linux on 1 platform by DEBIAN-CVE-2026-98570 (version 7.2.9-1), released October 19, 2026. It is not reported as exploited. Patch Radar priority: High.",
  "title": "net: ipv6: keep room for the mac header in dst_dev_overhead()",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  net: ipv6: keep room for the mac header in dst_dev_overhead()  The seg6, ioam6 and rpl lwtunnels size their skb_cow_head() request as the length they are about to push plus dst_dev_overhead(), then push the new headers and rebuild the mac header below them with skb_mac_header_rebuild().  That rebuild needs skb-\u003Emac_len of headroom, but dst_dev_overhead() leaves LL_RESERVED_SPACE() of the egress device, 16 bytes for plain Ethernet.  Where the mac header is longer than that, as it is on ingress through a VLAN device with reorder_hdr off, the rebuild runs out of room: skb_set_mac_header(skb, -skb-\u003Emac_len) computes a negative offset, stores it unchecked in the u16 skb-\u003Emac_header, and the memmove that follows writes skb-\u003Emac_len bytes about 64 KB past skb-\u003Ehead. Forwarding plain ping6 traffic through such a device reproduces it on all five seg6 encapsulation modes and on the rpl and ioam6 inline paths; skb-\u003Emac_header comes back as 65534 on a 704-byte head.  Return the larger of the two.  The helper already returns skb-\u003Emac_len when it has no dst, so this only makes the other branch agree, and it covers every caller rather than each call site in turn.",
  "published": "2026-10-18T16:17:09Z",
  "severity": "Important",
  "cvss": 7.4,
  "epss": 0.00189,
  "epssPercentile": 0.08596,
  "priority": "High",
  "priorityTier": 3,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "vendorAdvisory": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-98570",
  "fixes": [
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "7.2.9-1",
      "fix": "DEBIAN-CVE-2026-98570",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-98570",
      "released": "2026-10-19T16:27:52Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-09T01:18:40Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}