CVE-2026-52937: Linux kernel · tap: fix stack info leak in tap_ioctl() SIOCGIFHWADDR
Source GCVE Database
Not known to be exploited · CVSS 5.5 Medium · fixed in bddc09212c24934643bd44fc794748d2bbb3b6cd : update Linux kernel when convenient.
Data as of 30 Oct 2026, 16:33 UTC
Thin evidence
One scorer or none- Patch
- Available – fixed in bddc09212c24934643bd44fc794748d2bbb3b6cd, 8197905d97099d8b1e3883112bbb497abd20f9f0, 719007c3492f0f1f9e9cdbed8ac45ba45bb13eeb +6
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 24 Jun 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in– |
Description
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.
References
- nvd.nist.gov/vuln/detail/CVE-2026-52937 (opens in a new tab)
- git.kernel.org/stable/c/05305e832be7b9d65b2b72caacf7d850b3942b2a (opens in a new tab)
- git.kernel.org/stable/c/37d028a473b0826ad5970b52b791db4a29a23627 (opens in a new tab)
- git.kernel.org/stable/c/4b6dcfe0e3dfffd8057a4fc99b3f096c45709905 (opens in a new tab)
- git.kernel.org/stable/c/719007c3492f0f1f9e9cdbed8ac45ba45bb13eeb (opens in a new tab)
- git.kernel.org/stable/c/8197905d97099d8b1e3883112bbb497abd20f9f0 (opens in a new tab)
- git.kernel.org/stable/c/bddc09212c24934643bd44fc794748d2bbb3b6cd (opens in a new tab)