In the Linux kernel, the following vulnerability has been resolved: net/sched: reject overly deep qdisc hierarchies Deep qdisc hierarchies can lead… (CVE-2026-74663)
A vulnerability in the Linux kernel's network scheduler (net/sched) allowed overly deep queuing discipline (qdisc) hierarchies, which could cause excessive recursion and exhaust the kernel stack. The issue arose because the existing loop check did not cover the create-and-graft path, permitting the creation of deep qdisc hierarchies. The vulnerability has been resolved by storing and enforcing a maximum hierarchy depth in the qdisc structure, rejecting new child qdiscs beyond this limit.
AI Analysis
Technical Summary
The Linux kernel net/sched subsystem had a vulnerability (CVE-2026-74663) where deep qdisc hierarchies could lead to excessive recursion in qdisc tree walkers, potentially exhausting the kernel stack. The flaw was due to the loop check not covering the create-and-graft path, allowing the hierarchy to grow beyond safe limits. The fix involves tracking the hierarchy depth within the Qdisc structure and rejecting new child qdiscs once the maximum allowed depth is reached.
Potential Impact
Excessive recursion caused by deep qdisc hierarchies could exhaust the kernel stack, potentially leading to kernel crashes or denial of service conditions. No known exploits in the wild have been reported.
Mitigation Recommendations
A fix has been implemented in the Linux kernel to store and enforce a maximum depth for qdisc hierarchies, rejecting new child qdiscs beyond this limit. Users should update to a Linux kernel version that includes this fix. Patch status is not explicitly confirmed in the provided data; users should consult the official Linux kernel advisories or vendor updates for the exact fixed versions and apply updates accordingly.
In the Linux kernel, the following vulnerability has been resolved: net/sched: reject overly deep qdisc hierarchies Deep qdisc hierarchies can lead… (CVE-2026-74663)
Description
A vulnerability in the Linux kernel's network scheduler (net/sched) allowed overly deep queuing discipline (qdisc) hierarchies, which could cause excessive recursion and exhaust the kernel stack. The issue arose because the existing loop check did not cover the create-and-graft path, permitting the creation of deep qdisc hierarchies. The vulnerability has been resolved by storing and enforcing a maximum hierarchy depth in the qdisc structure, rejecting new child qdiscs beyond this limit.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The Linux kernel net/sched subsystem had a vulnerability (CVE-2026-74663) where deep qdisc hierarchies could lead to excessive recursion in qdisc tree walkers, potentially exhausting the kernel stack. The flaw was due to the loop check not covering the create-and-graft path, allowing the hierarchy to grow beyond safe limits. The fix involves tracking the hierarchy depth within the Qdisc structure and rejecting new child qdiscs once the maximum allowed depth is reached.
Potential Impact
Excessive recursion caused by deep qdisc hierarchies could exhaust the kernel stack, potentially leading to kernel crashes or denial of service conditions. No known exploits in the wild have been reported.
Mitigation Recommendations
A fix has been implemented in the Linux kernel to store and enforce a maximum depth for qdisc hierarchies, rejecting new child qdiscs beyond this limit. Users should update to a Linux kernel version that includes this fix. Patch status is not explicitly confirmed in the provided data; users should consult the official Linux kernel advisories or vendor updates for the exact fixed versions and apply updates accordingly.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-qwcm-6g6c-27vm
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-74663"]
- Ecosystems
- []
- Database Specific Severity
- null
- Cvss Version
- null
Threat ID: 6a8a27f1acd9273b499bc79c
Added to database: 08/22/2026, 22:51:29 UTC
Last enriched: 08/23/2026, 00:10:15 UTC
Last updated: 08/23/2026, 01:32:01 UTC
Views: 2
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