CVE Catalog

CVE-2026-90114

Low risk· EPSS 11%
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.22%

11th percentile - higher than 11% of all known CVEs

Summary

In the Linux kernel bridge subsystem, a pair of descending VLAN and tunnel ID ranges can pass the tunnel range span check. The VLAN subtraction produces a negative int converted to unsigned, which can equal the wrapped tunnel ID delta. The range loop then performs no iterations, leaving err uninitialized and making the return value unpredictable.

Risk Assessment

An unpredictable return value can lead to incorrect bridge behavior and potential stability issues. The vulnerability requires configuring descending VLAN/tunnel ranges.

Recommendation

Update the Linux kernel to a version with the fix that rejects descending VLAN ranges. Avoid configuring descending VLAN ranges in bridge settings.

Related vulnerabilities

Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS