CVE-2026-52937: Linux Kernel

Medium severity, CVSS 5.5. EPSS: 0.1% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: tap: fix stack info leak in tap_ioctl() SIOCGIFHWADDR In the SIOCGIFHWADDR path, tap_ioctl() copies 16 bytes of an uninitialised on-stack struct sockaddr_storage to userspace via ifr_hwaddr, but netif_get_mac_address() only writes sa_family and dev->addr_len (6 for Ethernet) bytes, leaving sa_data[6..13] uninitialised. Those 8 trailing bytes leak kernel stack contents; SIOCGIFHWADDR on a macvtap chardev returns kernel .text and direct-map pointers, defeating KASLR. Initialise ss at declaration.

Affected products

• Linux Linux Kernel: from 5.4.103, before 5.5 (fixed in 5.5); from 5.10.21, before 5.11 (fixed in 5.11); from 5.11.4, before 6.18.34 (fixed in 6.18.34); from 6.19, before 7.0.11 (fixed in 7.0.11); version 7.1 only

Published 2026-06-24. Last modified 2026-07-08.