CVE-2026-74739: net/sched: cls_u32: skip hash tables in u32_bind_class()
CSIRTS triage
- What
- The cls_u32 scheduler class fails to skip hash tables during class binding, allowing privilege escalation or DoS.
- Who is affected
- Linux systems with cls_u32 traffic control classes and eBPF programs.
- Urgency
- High severity (CVSS 7.1) and not exploited; apply kernel patch promptly.
- Action
- Update Linux kernel to fix cls_u32 to skip hash tables in u32_bind_class().
AI-assisted analysis generated from the source advisory — verify against the original.
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Details
Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-74739
Exploitation outlook
EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.
- Low exploitation riskCVE-2026-747390.14% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 4% of all EPSS-scored CVEs.
Referenced CVEs
| CVE | CSIRTS overview | External |
|---|---|---|
| CVE-2026-74739 | coverage & exploitation status | NVD · CVE.org |
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