CVE-2026-90114 net: bridge: Reject descending VLAN tunnel ranges
An integer overflow in Linux kernel bridge VLAN tunnel range checks can cause unpredictable return values and potential denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-90114?
CVE-2026-90114 is a vulnerability in Linux, published on 17 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
net: bridge: Reject descending VLAN tunnel ranges
A pair of descending VLAN and tunnel IDs can pass the tunnel range span check. The VLAN subtraction produces a negative int, which is converted to unsigned when compared with the u32 tunnel ID subtraction. It can therefore equal the wrapped tunnel ID delta.
The range loop then performs no iterations. Since the batched notification handling added a post-loop error check, this leaves err uninitialized and makes the request's return value unpredictable.
Reject descending VLAN ranges before comparing the spans. Valid ascending and single-entry ranges remain unchanged, while malformed descending ranges consistently return -EINVAL.
This issue was found by a static analysis checker and confirmed by manual source review.
Which versions are affected by CVE-2026-90114?
How do I fix CVE-2026-90114?
Apply the vendor's patch.
Is CVE-2026-90114 being exploited?
There is no known exploitation of CVE-2026-90114 in the wild and no public exploit code.
Sources
Also known as AZL-102212, BELL-CVE-2026-90114, DEBIAN-CVE-2026-90114, GHSA-3m56-382v-r3qq, UBUNTU-CVE-2026-90114.