CVE-2026-31472

publishedCWE-835

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.

Technical severity5.5 mediumCVSS 3.1 · NVD: [email protected]

Published2026-04-22Source updated 2026-11-11

Collected2026-11-121 attributed source

Fixes and workarounds

Fix

The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.

Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67

Fix

The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.

Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67

Fix

The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.

Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67

Affected products and versions

Affected products, source version ranges and reporting authorities
Product	Versions	Authority
linux_kernel linux	≥ 6.14.1; < 6.18.21 (affected, custom)	NVD
linux_kernel linux	≥ 6.19; < 6.19.11 (affected, custom)	NVD
linux_kernel linux	6.14 (affected, custom)	NVD
linux_kernel linux	7.0 (affected, custom)	NVD

Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.

NVD applicability configurations (1)

These expressions retain AND/OR operators, negation, and required environmental products. A listed product is not sufficient to establish exposure when additional conditions apply.

[
  {
    "negate": false,
    "nodes": [
      {
        "cpeMatch": [
          {
            "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
            "versionEndExcluding": "6.18.21",
            "versionStartIncluding": "6.14.1",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
            "versionEndExcluding": "6.19.11",
            "versionStartIncluding": "6.19",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:o:linux:linux_kernel:6.14:-:*:*:*:*:*:*",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:*",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:*",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc7:*:*:*:*:*:*",
            "vulnerable": true
          }
        ],
        "negate": false,
        "operator": "OR"
      }
    ],
    "operator": "OR"
  }
]

CVSS assessments

CVSS scores, vectors and reporting authorities
Version / score	Vector	Authority
3.1 / 5.5 medium	`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`	NVD: [email protected]

Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

References

https://git.kernel.org/stable/c/0d10393d5eac33cbd92f7a41fddca12c41d3cb7e416baaa9-dc9f-4396-8d5f-8c081fb06d67 · Patch
https://git.kernel.org/stable/c/3db7d4f777a00164582061ccaa99569cd85011a3416baaa9-dc9f-4396-8d5f-8c081fb06d67 · Patch
https://git.kernel.org/stable/c/de6d8e8ce5187f7402c9859b443355e7120c5f09416baaa9-dc9f-4396-8d5f-8c081fb06d67 · Patch

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