CVE-2026-74739
CVE CVE-2026-74739EUVD EUVD-2026-66569Published 2026-08-26T14:36:51.000ZLast changed 2026-08-27T05:01:00.000ZCVSS 7.8
What the advisory describes
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.
Source: EUVD (ENISA), in the words of the advisory.
Products the advisory names
These come from the advisory itself, not from any check we performed.
- Linux — Linux patch: 7.1.10; 07d79fc7d94e3f884b8b1c95aa615b202bb5e4c1 <31f26a95eeee926946809ac456c61a3217936a62; 07d79fc7d94e3f884b8b1c95aa615b202bb5e4c1 <19d114b93c94bdef70496f26685c2a6b242f41b3; 07d79fc7d94e3f884b8b1c95aa615b202bb5e4c1 <6d3724e616faf952c3adcf8414fc21a828ef3709; 07d79fc7d94e3f884b8b1c95aa615b202bb5e4c1 <ec5f3005586a785689fd568361b0c5925cb1548b; patch: 6.12.105; 07d79fc7d94e3f884b8b1c95aa615b202bb5e4c1 <e71f8e9ed6f311410b14741f6012afe01869c0fa; patch: 6.1.184; patch: 6.6.153; patch: 7.2; patch: 6.18.46; 4.14; patch: 0; 07d79fc7d94e3f884b8b1c95aa615b202bb5e4c1 <594a064d603202b9ee21e07679d854e5c1750cc4
The versions shown are the advisory's own. Patchlage compares no version numbers and derives no judgement from them — which version is installed is something a person has to look up.
Carried in the product catalogue
An estate covering these products can be recorded in Patchlage. An advisory about them appears in the next morning's situation report.
- Linux — Linux
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