CVE-2025-40173
Published: November 14, 2025Last modified: June 24, 2026
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.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 7.8 |
| Attack Vector | LOCAL |
| Attack complexity | LOW |
| Privileges required | LOW |
| User interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality | HIGH |
| Integrity impact | HIGH |
| Availability impact | HIGH |
| Vector | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | 23 LTS | linux-lts | Fixed (6.1.158-r0) |
| 25 LTS | linux-lts | Fixed (6.12.57-r0) | |
| Stream | linux-lts | Fixed (6.18.35-r1) |
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