How severe is CVE-2026-49427?

CVE-2026-49427 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-49427 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (41st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-49427?

CVE-2026-49427 primarily affects Freebsd. In total, 38 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-49427?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2026-49427 published?

CVE-2026-49427 was published on 2026-08-19 and last updated on 2026-09-01.

CVE-2026-49427

CVE-2026-49427 is a high-severity vulnerability in Freebsd with a CVSS 3.x base score of 8.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-826.

Key facts

Severity: High (CVSS 3.x base score 8.8)
EPSS exploit prediction: 1% (41st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-826
Affected product: Freebsd
Published: 2026-08-19
Last modified: 2026-09-01

Description

Pages belonging to largepage shared memory objects were not explicitly wired. When sendfile(2) transmitted such an object with the SF_NOCACHE flag, it freed the underlying pages after transmission even though existing mappings still referred to them. An unprivileged local user can abuse the bug to access freed kernel memory. This can be exploited to escalate privileges.

Frequently asked questions

What is CVE-2026-49427?: Pages belonging to largepage shared memory objects were not explicitly wired. When sendfile(2) transmitted such an object with the SF_NOCACHE flag, it freed the underlying pages after transmission even though existing mappings still referred to them. An unprivileged local user can abuse the bug to access freed kernel memory. This can be exploited to escalate privileges.
How severe is CVE-2026-49427?: CVE-2026-49427 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-49427 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (41st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-49427?: CVE-2026-49427 primarily affects Freebsd. In total, 38 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-49427?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2026-49427 published?: CVE-2026-49427 was published on 2026-08-19 and last updated on 2026-09-01.

References

https://security.freebsd.org/advisories/FreeBSD-SA-26:44.posixshm.asc

Affected products (38)

cpe:2.3:o:freebsd:freebsd:14.3:-:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:14.3:p1:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:14.3:p10:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:14.3:p11:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:14.3:p12:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:14.3:p13:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:14.3:p14:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:14.3:p15:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:14.3:p2:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:14.3:p3:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:14.3:p4:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:14.3:p5:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:14.3:p6:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:14.3:p7:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:14.3:p8:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:14.3:p9:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:14.4:-:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:14.4:p1:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:14.4:p2:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:14.4:p3:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:14.4:p4:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:14.4:p5:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:14.4:p6:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:14.4:rc1:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:15.0:-:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:15.0:p1:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:15.0:p10:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:15.0:p2:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:15.0:p3:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:15.0:p4:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:15.0:p5:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:15.0:p6:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:15.0:p7:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:15.0:p8:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:15.0:p9:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:15.1:-:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:15.1:rc2:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:15.1:rc3-p1:*:*:*:*:*:*

More vulnerabilities in Freebsd

CVE-2024-43102 — Critical (CVSS 10.0): Concurrent removals of certain anonymous shared memory mappings by using the UMTX_SHM_DESTROY sub-request of…
CVE-2018-17160 — Critical (CVSS 10.0): In FreeBSD before 11.2-STABLE(r341486) and 11.2-RELEASE-p6, insufficient bounds checking in one of the device models…
CVE-2014-3954 — Critical (CVSS 10.0): Stack-based buffer overflow in rtsold in FreeBSD 9.1 through 10.1-RC2 allows remote attackers to cause a denial of…
CVE-2011-4862 — Critical (CVSS 10.0): Buffer overflow in libtelnet/encrypt.c in telnetd in FreeBSD 7.3 through 9.0, MIT Kerberos Version 5 Applications (aka…
CVE-2006-4304 — Critical (CVSS 10.0): Buffer overflow in the sppp driver in FreeBSD 4.11 through 6.1, NetBSD 2.0 through 4.0 beta before 20060823, and…
CVE-2006-0226 — Critical (CVSS 10.0): Integer overflow in IEEE 802.11 network subsystem (ieee80211_ioctl.c) in FreeBSD before 6.0-STABLE, while scanning for…

All CVEs affecting Freebsd →

Other CWE-826 vulnerabilities

CVE-2026-31663 — High (CVSS 7.8): In the Linux kernel, the following vulnerability has been resolved: xfrm: hold dev ref until after transport_finish…
CVE-2024-51727 — Medium (CVSS 6.5): Ruijie Reyee OS versions 2.206.x up to but not including 2.320.x contains a feature that could enable attackers to…
CVE-2023-1297 — Medium (CVSS 4.9): Consul and Consul Enterprise's cluster peering implementation contained a flaw whereby a peer cluster with service of…
CVE-2024-58249 — Low (CVSS 3.7): In wxWidgets before 3.2.7, a crash can be triggered in wxWidgets apps when connections are refused in wxWebRequestCURL.
CVE-2025-24912 — Low (CVSS 3.7): hostapd fails to process crafted RADIUS packets properly. When hostapd authenticates wi-fi devices with RADIUS…

Browse all CWE-826 vulnerabilities →