MEDIUM CISA KEV

CVE-2026-53266

CVSS v3

6.8

MEDIUM

EPSS Score

0.8 %

exploit probability, as of 2026-10-19

CISA KEV

Yes

known exploited

Exploitation

—

SSVC status

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Affected and fixed versions

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

kernelAlmaLinux:9all versions · fixed in 5.14.0-687.23.1.el9_8and 73 other packages
kernel-develAlmaLinux:10all versions · fixed in 6.12.0-211.59.1.el10_2and 13 other packages

Vendor advisories

CVE-2026-53266 Red Hat Product Security2,336 products fixed · 22 known affected
kernel: netfilter: ebtables SNAT target writes to shared memory pages during ARP hardware address rewrite
kernel-rt as a component of Red Hat Enterprise Linux 9 · kernel-rt-core as a component of Red Hat Enterprise Linux 9 · kernel-rt-debug as a component of Red Hat Enterprise Linux 9
RHSA-2026:73732 Red Hat Product Security56 products fixed
Red Hat Security Advisory: kernel security update
RHSA-2026:72059 Red Hat Product Security53 products fixed
Red Hat Security Advisory: kernel security update
RHSA-2026:71687 Red Hat Product Security93 products fixed
Red Hat Security Advisory: kernel security update
RHSA-2026:71657 Red Hat Product Security12 products fixed
Red Hat Security Advisory: kernel-rt security update
RHSA-2026:71569 Red Hat Product Security233 products fixed
Red Hat Security Advisory: kernel security update

11 more advisories

Full record on NVD

Description

Microsoft Security Update (CVE-2026-53266)

CISA Known Exploited Vulnerability

Date Added: 2026-09-18
Patch Due Date: 2026-09-21
Ransomware Use: Unknown

Technical details

CVSS v3 Vector: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H/E:U
Published: 2026-07-03
MSRC Title: netfilter: bridge: make ebt_snat ARP rewrite writable

Frequently asked questions

What is CVE-2026-53266?

Microsoft Security Update (CVE-2026-53266)

Is CVE-2026-53266 actively exploited?

Yes. CVE-2026-53266 is on the CISA Known Exploited Vulnerabilities (KEV) catalog, meaning it has been confirmed as actively exploited in the wild. CISA requires federal agencies to patch by 2026-09-21.

What is the CVSS score for CVE-2026-53266?

CVE-2026-53266 has a CVSS v3 base score of 6.8 (MEDIUM severity), with vector string CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H/E:U.

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