Medium 5.5Published Jun 24, 2026

CVE-2026-52937tap: fix stack info leak in tap_ioctl() SIOCGIFHWADDR

Updated under an hour ago (Oct 27, 2026, 10:40 PM ET)

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Exploited in the last 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.

CVSS: 5.5 MEDIUM (v3.1, NVD)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE): Not given
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Modified
Record last updated: Oct 21, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	from 3b23a32a63219f51a5298bc55a65ecee866e79d0 before 37d028a473b0826ad5970b52b791db4a29a23627; from 3b23a32a63219f51a5298bc55a65ecee866e79d0 before 8197905d97099d8b1e3883112bbb497abd20f9f0; from 3b23a32a63219f51a5298bc55a65ecee866e79d0 before 719007c3492f0f1f9e9cdbed8ac45ba45bb13eeb; from 3b23a32a63219f51a5298bc55a65ecee866e79d0 before 05305e832be7b9d65b2b72caacf7d850b3942b2a; from 3b23a32a63219f51a5298bc55a65ecee866e79d0 before bddc09212c24934643bd44fc794748d2bbb3b6cd; 176188cff67ec1aa55103647b61d02315cc38e98; 1fc205d9e400f069ebf30d3faa6ec2bab2cbd7b4; 4d0ae760c02c98fc78b78d3a0509896bc648ad1c; and 3 more ranges	CNA record
linux linux_kernel linux:linux_kernel	from 5.4.103 before 5.5; from 5.10.21 before 5.11; from 5.11.4 before 6.18.34; from 6.19 before 7.0.11; 7.1; 7.1; 7.1; 7.1	NVD

References

References

https://git.kernel.org/stable/c/37d028a473b0826ad5970b52b791db4a29a23627
https://git.kernel.org/stable/c/8197905d97099d8b1e3883112bbb497abd20f9f0
https://git.kernel.org/stable/c/719007c3492f0f1f9e9cdbed8ac45ba45bb13eeb	patch
https://git.kernel.org/stable/c/05305e832be7b9d65b2b72caacf7d850b3942b2a	patch
https://git.kernel.org/stable/c/bddc09212c24934643bd44fc794748d2bbb3b6cd	patch

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.