What’s Vulnerable › Vulnerabilities

CVE-2026-72350: netfilter: xt_u32: reject invalid shift counts

• Severity: high (CVSS 7.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-08-15 · updated 2026-10-16

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.

Affected products

• Linux kernel: 2.6.23 — fixed in 7.2

How to fix

Upgrade to a fixed version: Linux kernel 7.2. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/00d034fe8230dfc5832fe011ff2d81c1a2cc7a29
• https://git.kernel.org/stable/c/0a8b7a6d763775709c601f584e709ae48bcc000a
• https://git.kernel.org/stable/c/64cdf7d30ac18e43df6c48004435febb965809a8
• https://git.kernel.org/stable/c/728f479dc0447ae7eaef87926ff49142e415a811
• https://git.kernel.org/stable/c/a597a722fb71a534138c20359b655726622b5f17
• https://git.kernel.org/stable/c/b33b44250d57ab0e5a1e2571b5285fb0d0a7f382
• https://git.kernel.org/stable/c/ca7c92d9701249e6daf132087756a88cbf2bb2a3
• https://git.kernel.org/stable/c/cce42014415cecd98aa49b3950e7b02ee7c81268

Get alerted when CVE-2026-72350 or the next vulnerability affects your stack