Medium · CVSS 5.5CVE-2026-52937

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

Answer in brief

CVE-2026-52937 records a Medium severity (CVSS 5.5) vulnerability in tap: fix stack info leak in tap_ioctl() SIOCGIFHWADDR. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Jun 24, 2026Updated Oct 21, 2026Source checked Oct 21, 2026First seen by HOL Jun 24, 2026Material review Oct 21, 2026

Upstream Advisory

Key facts

Risk: Medium · CVSS 5.5
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

CVSS is 5.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Linux/Linuxgeneric	>=3b23a32a63219f51a5298bc55a65ecee866e79d0 <37d028a473b0826ad5970b52b791db4a29a23627 \|\| >=3b23a32a63219f51a5298bc55a65ecee866e79d0 <8197905d97099d8b1e3883112bbb497abd20f9f0 \|\| >=3b23a32a63219f51a5298bc55a65ecee866e79d0 <719007c3492f0f1f9e9cdbed8ac45ba45bb13eeb \|\| >=3b23a32a63219f51a5298bc55a65ecee866e79d0 <05305e832be7b9d65b2b72caacf7d850b3942b2a \|\| >=3b23a32a63219f51a5298bc55a65ecee866e79d0 <bddc09212c24934643bd44fc794748d2bbb3b6cd \|\| 176188cff67ec1aa55103647b61d02315cc38e98 \|\| 1fc205d9e400f069ebf30d3faa6ec2bab2cbd7b4 \|\| 4d0ae760c02c98fc78b78d3a0509896bc648ad1c \|\| >=5.4.103 <5.5 \|\| >=5.10.21 <5.11 \|\| >=5.11.4 <5.12	37d028a473b0826ad5970b52b791db4a29a23627, 8197905d97099d8b1e3883112bbb497abd20f9f0, 719007c3492f0f1f9e9cdbed8ac45ba45bb13eeb, 05305e832be7b9d65b2b72caacf7d850b3942b2a, bddc09212c24934643bd44fc794748d2bbb3b6cd, 5.5, 5.11, 5.12
Linux/Linuxgeneric	5.12	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to 37d028a473b0826ad5970b52b791db4a29a23627 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Jun 24, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Oct 21, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Jun 24, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.