{"cve":"CVE-2025-40173","nvd":{"published":"2025-11-12T11:15:47.780","modified":"2026-10-19T21:10:00.160","status":"Deferred","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/ip6_tunnel: Prevent perpetual tunnel growth\n\nSimilarly to ipv4 tunnel, ipv6 version updates dev->needed_headroom, too.\nWhile ipv4 tunnel headroom adjustment growth was limited in\ncommit 5ae1e9922bbd (\"net: ip_tunnel: prevent perpetual headroom growth\"),\nipv6 tunnel yet increases the headroom without any ceiling.\n\nReflect ipv4 tunnel headroom adjustment limit on ipv6 version.\n\nCredits to Francesco Ruggeri, who was originally debugging this issue\nand wrote local Arista-specific patch and a reproducer.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8},"cwes":[],"references":["https://git.kernel.org/stable/c/10fe967efe73c610e526ff7460581610633dee9c","https://git.kernel.org/stable/c/11f6066af3bfb8149aa16c42c0b0c5ea5b199a94","https://git.kernel.org/stable/c/21f4d45eba0b2dcae5dbc9e5e0ad08735c993f16","https://git.kernel.org/stable/c/402b6985e872b4cf394bbbf33b503947a326a6cb","https://git.kernel.org/stable/c/48294a67863c9cfa367abb66bbf0ef6548ae124f"],"products":[],"source":"nvd","synced_at":"2026-10-21T03:43:09.190223697+00:00"},"epss":{"cve":"CVE-2025-40173","score":0.00153,"percentile":0.04397,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}