Vulnerability in Linux
CVE-2026-31472
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.002 (4.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 4th percentile — 4.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.001 · newest: 0.002 · change: +0.000
Affected products
- Linux — versions 6c82d2433671819a550227bf65bfb6043e3d3305, 6.14, 0
- Linux Kernel — versions 6.14, 7.0
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-31472?
- CVE-2026-31472 is a medium-severity vulnerability in Linux, classified under Loop with Unreachable Exit Condition (Infinite Loop). CVSS score: 5.5/10. Published 2026-04-22.
- How severe is CVE-2026-31472?
- Medium severity. CVSS v3 base score is 5.5 out of 10.