CVE Catalog

CVE-2026-74663

HighCVSS 7.8
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.13%

3th percentile - higher than 3% of all known CVEs

Summary

In the Linux kernel net/sched subsystem, overly deep qdisc hierarchies can cause excessive recursion and kernel stack exhaustion. The existing loop check does not cover the create-and-graft path, allowing hierarchy extension.

Risk Assessment

An attacker could create a very deep qdisc hierarchy, leading to kernel stack overflow and system crash (DoS).

Recommendation

Apply the kernel patch that stores hierarchy depth in struct Qdisc and rejects new children beyond the maximum depth.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: net/sched: reject overly deep qdisc hierarchies Deep qdisc hierarchies can lead to excessive recursion in qdisc tree walkers and exhaust the kernel stack. The existing loop check does not cover the create-and-graft path, so a hierarchy can still be extended by creating a new child qdisc below an already deep parent. Store the hierarchy depth in struct Qdisc and update it when qdiscs are grafted. Reject new child qdiscs once the parent is already at the maximum allowed depth.

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