Description
In the Linux kernel, the following vulnerability has been resolved: netfilter: xt_u32: reject invalid shift counts u32_match_it() executes rule-supplied shift operands on a 32-bit value. A malformed u32 rule can provide a shift count of 32 or more, triggering an undefined shift out-of-bounds during packet evaluation. Validate XT_U32_LEFTSH and XT_U32_RIGHTSH operands in u32_mt_checkentry() and reject malformed rules before they reach the packet path.
References8
- git.kernel.org/stable/c/00d034fe8230dfc5832fe011ff2d81c1a2cc7a29
- git.kernel.org/stable/c/0a8b7a6d763775709c601f584e709ae48bcc000a
- git.kernel.org/stable/c/64cdf7d30ac18e43df6c48004435febb965809a8
- git.kernel.org/stable/c/728f479dc0447ae7eaef87926ff49142e415a811
- git.kernel.org/stable/c/a597a722fb71a534138c20359b655726622b5f17
- git.kernel.org/stable/c/b33b44250d57ab0e5a1e2571b5285fb0d0a7f382
- git.kernel.org/stable/c/ca7c92d9701249e6daf132087756a88cbf2bb2a3
- git.kernel.org/stable/c/cce42014415cecd98aa49b3950e7b02ee7c81268
Metrics
- CVSS 3.1
-
7.8
HIGH
Score source: CNA
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - EPSS — exploit probability
- 0% percentile: 7 · as of 11 November 2026
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