CVE-2026-31472 (GCVE-0-2026-31472)

Vulnerability from cvelistv5 – Published: 2026-04-22 13:54 – Updated: 2026-04-22 13:54
VLAI?
Title
xfrm: iptfs: validate inner IPv4 header length in IPTFS payload
Summary
In the Linux kernel, the following vulnerability has been resolved: xfrm: iptfs: validate inner IPv4 header length in IPTFS payload Add validation of the inner IPv4 packet tot_len and ihl fields parsed from decrypted IPTFS payloads in __input_process_payload(). A crafted ESP packet containing an inner IPv4 header with tot_len=0 causes an infinite loop: iplen=0 leads to capturelen=min(0, remaining)=0, so the data offset never advances and the while(data < tail) loop never terminates, spinning forever in softirq context. Reject inner IPv4 packets where tot_len < ihl*4 or ihl*4 < sizeof(struct iphdr), which catches both the tot_len=0 case and malformed ihl values. The normal IP stack performs this validation in ip_rcv_core(), but IPTFS extracts and processes inner packets before they reach that layer.
Severity ?
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: 6c82d2433671819a550227bf65bfb6043e3d3305 , < de6d8e8ce5187f7402c9859b443355e7120c5f09 (git)
Affected: 6c82d2433671819a550227bf65bfb6043e3d3305 , < 3db7d4f777a00164582061ccaa99569cd85011a3 (git)
Affected: 6c82d2433671819a550227bf65bfb6043e3d3305 , < 0d10393d5eac33cbd92f7a41fddca12c41d3cb7e (git)
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    Linux Linux Affected: 6.14
Unaffected: 0 , < 6.14 (semver)
Unaffected: 6.18.21 , ≤ 6.18.* (semver)
Unaffected: 6.19.11 , ≤ 6.19.* (semver)
Unaffected: 7.0 , ≤ * (original_commit_for_fix)
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{
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          "product": "Linux",
          "programFiles": [
            "net/xfrm/xfrm_iptfs.c"
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      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: iptfs: validate inner IPv4 header length in IPTFS payload\n\nAdd validation of the inner IPv4 packet tot_len and ihl fields parsed\nfrom decrypted IPTFS payloads in __input_process_payload(). A crafted\nESP packet containing an inner IPv4 header with tot_len=0 causes an\ninfinite loop: iplen=0 leads to capturelen=min(0, remaining)=0, so the\ndata offset never advances and the while(data \u003c tail) loop never\nterminates, spinning forever in softirq context.\n\nReject inner IPv4 packets where tot_len \u003c ihl*4 or ihl*4 \u003c sizeof(struct\niphdr), which catches both the tot_len=0 case and malformed ihl values.\nThe normal IP stack performs this validation in ip_rcv_core(), but IPTFS\nextracts and processes inner packets before they reach that layer."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-04-22T13:54:00.281Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
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          "url": "https://git.kernel.org/stable/c/3db7d4f777a00164582061ccaa99569cd85011a3"
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        {
          "url": "https://git.kernel.org/stable/c/0d10393d5eac33cbd92f7a41fddca12c41d3cb7e"
        }
      ],
      "title": "xfrm: iptfs: validate inner IPv4 header length in IPTFS payload",
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  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-31472",
    "datePublished": "2026-04-22T13:54:00.281Z",
    "dateReserved": "2026-03-09T15:48:24.098Z",
    "dateUpdated": "2026-04-22T13:54:00.281Z",
    "state": "PUBLISHED"
  },
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  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
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  }
}


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  • Confirmed: The vulnerability has been validated from an analyst's perspective.
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