In the Linux kernel, the following vulnerability has been resolved: net/ip6_tunnel: Prevent perpetual tunnel growth Similarly to ipv4 tunnel, ipv6 version updates dev->needed_headroom, too. While ipv4 tunnel headroom adjustment growth was limited in commit 5ae1e9922bbd ("net: ip_tunnel: prevent perpetual headroom growth"), ipv6 tunnel yet increases the headroom without any ceiling. Reflect ipv4 tunnel headroom adjustment limit on ipv6 version. Credits to Francesco Ruggeri, who was originally debugging this issue and wrote local Arista-specific patch and a reproducer.
Conclusion & alert: CVE-2025-40173 is rated Low Risk (18.2/100): low exploitation likelihood (EPSS 0.06%). Mandatory action: Low composite risk—no urgent action required; patch on your normal maintenance cycle and revisit priority if CVSS or EPSS increases.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-04-22 | 0.04% | 0.06% | +0.01% |
| 2 | 2026-04-10 | 0.06% | 0.04% | -0.02% |
| 3 | 2025-12-18 | — | 0.06% | — |
Full EPSS history (4 records total)
CVSS metrics for this CVE.
No CVSS data in dataset for this CVE.
| vendor | priority | summary | link |
|---|---|---|---|
debian
|
not yet assigned | CVE-2025-40173 not yet assigned priority: Debian including 2 source packages (linux, linux-6.1), 6 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 6. | https://security-tracker.debian.org/tracker/CVE-2025-40173 |
redhat
|
medium | — | https://access.redhat.com/security/cve/CVE-2025-40173 |
suse
|
medium | — | https://www.suse.com/security/cve/CVE-2025-40173/ |
ubuntu
|
medium | CVE-2025-40173 medium priority: Ubuntu including 157 source packages (linux, linux-allwinner-5.19, …), 1405 status rows across 9 suites (bionic, focal, jammy, noble, plucky, questing, trusty, upstream, xenial): DNE 1010, ignored 178, released 158, needed 45, not-affected 11, pending 3. | https://ubuntu.com/security/CVE-2025-40173 |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| No affected products in dataset. | |||