In the Linux kernel, the following vulnerability has been resolved: netfilter: ipset: stop hash:* range iteration at end The following hash set variants: hash:ip,mark hash:ip,port hash:ip,port,ip hash:ip,port,net iterate IPv4 ranges with a 32-bit iterator. The iterator must stop once the last address in the requested range has been processed. Advancing it once more can move the traversal state past the end of the request, so a later retry may continue from an unintended position. Handle the iterator increment explicitly at the end of the loop and stop once the upper bound has been processed. This keeps the existing retry behaviour intact for valid ranges while preventing traversal from continuing past the original boundary.

A flaw was found in the Linux kernel's netfilter ipset component. Specifically, certain hash set variants (such as hash:ip,mark and hash:ip,port) that iterate IPv4 ranges with a 32-bit iterator do not correctly stop at the end of the requested range. This can cause the iteration to advance beyond the intended boundary, potentially leading to a later retry continuing from an unintended position. This issue could result in incorrect processing of network rules or unexpected system behavior.

Red Hat Enterprise Linux 10 Fix deferred kernel Red Hat Enterprise Linux 6 Out of support scope kernel Red Hat Enterprise Linux 7 Fix deferred kernel Red Hat Enterprise Linux 7 Fix deferred kernel-rt Red Hat Enterprise Linux 8 Fix deferred kernel Red Hat Enterprise Linux 8 Fix deferred kernel-rt Red Hat Enterprise Linux 9 Fix deferred kernel Red Hat Enterprise Linux 9 Fix deferred kernel-rt https://www.cve.org/CVERecord?id=CVE-2026-52921 https://nvd.nist.gov/vuln/detail/CVE-2026-52921 https://lore.kernel.org/linux-cve-announce/2026062430-CVE-2026-52921-0628@gregkh/T