Kernel stack disclosure in Linux compatibility layer

published 2026-08-19 2 mo ago modified 2026-10-27 13 d ago also EUVD-2026-62345

cvss: 5.5; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.2%; EPSS 0.2% chance of exploitation in 30 days, percentile 4%
public exploits: 0; none known

The Linux waitid() implementation translates a FreeBSD siginfo_t struct into a stack-declared Linux siginfo_t. It did not first zero the stack struct.

An unprivileged user may observe 104 bytes of uninitialized kernel stack data, which may contain sensitive information.

Patch / fix

fixed in 1

FreeBSD FreeBSD p7, p11, p16

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 2 mo ago (2026-08-26)

Exploit prediction

0.15% chance of exploitation in the next 30 days, higher than 4% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CISA ADP	3.1	5.5	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
CNA	3.1	5.5	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Affected products

FreeBSD FreeBSD

Classification

Weakness

CWE-908 Use of Uninitialized Resource

References

security.freebsd.org /advisories/FreeBSD-SA-26:47.linux.asc
vendor-advisory

Sources

CVE List CVE-2026-49424
NVD CVE-2026-49424

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary