In the Linux kernel, the following vulnerability has been resolved: net/sched: cls_u32: skip hash tables in u32_bind_class() u32_walk()…
CVE-2026-74739 · published 26 Aug 2026
How serious is it
- Severity: high, CVSS score 7.8 out of 10.
- No exploit prediction (EPSS) score yet.
- Not on the CISA list of exploited vulnerabilities.
- No public exploit in Exploit-DB.
Is your app affected by CVE-2026-74739?
Paste this prompt into Claude Code, Cursor or any AI coding tool: it runs a free Shippable scan of your project and fixes what it finds. Built with Lovable, Bolt or v0? Scan your live app. Or upload your package file.
Who is affected
- Linux Linux: 4.14
How to check
- Find out whether you run the affected product and which version, then compare it with the versions above.
How to fix
Copies a prompt for Claude Code, Cursor or Codex that asks it to check whether you run this product.
- Apply the vendor's update or mitigation from the references below. If there is none yet, limit exposure of the affected service until there is.
- If a vulnerable version was live, check your logs and rotate the secrets that server could read.
The advisory
In the Linux kernel, the following vulnerability has been resolved:
net/sched: cls_u32: skip hash tables in u32_bind_class()
u32_walk() enumerates both struct tc_u_hnode and struct tc_u_knode
through the walker callback. u32_bind_class() unconditionally casts the
passed fh to tc_u_knode and accesses &n->res, so when fh is actually a
tc_u_hnode, which has no tcf_result member, this results in a
slab-out-of-bounds read of res->classid in tc_cls_bind_class().
The issue can be reproduced with the following commands:
tc qdisc add dev lo root handle 1: hfsc
tc class add dev lo parent 1: classid 1:1 hfsc sc rate 1000kbit
tc filter add dev lo parent 1:1 protocol ip prio 1 u32 match u32 0 0 flowid 1:1
tc class add dev lo parent 1: classid 1:2 hfsc sc rate 2000kbit
Fix this by skipping hash tables via the TC_U32_KEY(handle) check.
Check your whole app
Dependencies are only half of it. Free and read-only: before you push, run npx shippable-dev scan localhost:3000 in your project folder, no account needed. For your live app, you prove it's yours with a one-line tag first.
References
- git.kernel.org/stable/c/19d114b93c94bdef70496f26685c2a6b242f41b3
- git.kernel.org/stable/c/31f26a95eeee926946809ac456c61a3217936a62
- git.kernel.org/stable/c/594a064d603202b9ee21e07679d854e5c1750cc4
- git.kernel.org/stable/c/6d3724e616faf952c3adcf8414fc21a828ef3709
- git.kernel.org/stable/c/e71f8e9ed6f311410b14741f6012afe01869c0fa
- git.kernel.org/stable/c/ec5f3005586a785689fd568361b0c5925cb1548b
Merged from NVD. Last updated 24 Oct 2026. All vulnerabilities · RSS · JSON