VulnerabilityPublished 24 Jun 2026Updated 21 Oct 2026

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

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in bddc09212c24934643bd44fc794748d2bbb3b6cd : update Linux kernel when convenient.

Data as of 26 Oct 2026, 13:47 UTC

Severity

Unrated

Rated by Threat Radar · No CVSS score from NVD or the CNA

EPSS: 0.1% chance of exploitation in 30 days – higher than 1% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in bddc09212c24934643bd44fc794748d2bbb3b6cd, 8197905d97099d8b1e3883112bbb497abd20f9f0, 719007c3492f0f1f9e9cdbed8ac45ba45bb13eeb +5

Exploitation evidence

Disclosed: evidence found.
CVE published 24 Jun 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected >=5.4.103 <5.5 >=5.10.21 <5.11 >=5.11.4 <5.12	Fixed in bddc09212c24934643bd44fc794748d2bbb3b6cd 8197905d97099d8b1e3883112bbb497abd20f9f0 719007c3492f0f1f9e9cdbed8ac45ba45bb13eeb 05305e832be7b9d65b2b72caacf7d850b3942b2a 37d028a473b0826ad5970b52b791db4a29a23627 5.12 5.11 5.5
LinuxLinux	Affected =5.12	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

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