Vulnerability Description
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.
CVSS Score
HIGH
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
- https://git.kernel.org/stable/c/566f8d5c8a443f2dd69c5460fdec43ed1c870c65
- https://git.kernel.org/stable/c/b6eb25d870f1a8ae571fd3da2244b71df547824b
- https://git.kernel.org/stable/c/eeb4345488672584db4f8c20a1ae13a212ce31c4
FAQ
What is CVE-2025-40173?
CVE-2025-40173 is a vulnerability with a CVSS score of 7.8 (HIGH). 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 ip...
How severe is CVE-2025-40173?
CVE-2025-40173 has been rated HIGH with a CVSS base score of 7.8/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2025-40173?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.