CVE-2026-74723: btrfs: lzo: reject inline extents without valid headers

CSIRTS triage

What

The btrfs lzo decompression code accepts inline extents without valid headers.

Who is affected

Systems running affected Linux kernel versions with btrfs filesystems using LZO compression.

Urgency

Medium severity (CVSS 5.1); not currently exploited but impacts filesystem integrity.

Action

Update to a patched Linux kernel version addressing CVE-2026-74723.

AI-assisted analysis generated from the source advisory — verify against the original.

Details

Source

Microsoft Security Response Center (INTL · vendor-psirt · site)

Severity

medium — CVSS 5.1

Published

2026-08-11

Exploitation

Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-74723

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

• Low exploitation riskCVE-2026-747230.15% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 5% of all EPSS-scored CVEs.

Referenced CVEs

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

• criticalCVE-2026-74723: In the Linux kernel, the following vulnerability has been resolved: btrfs: lzo: reject inline …nvd

More from Microsoft Security Response Center

• lowCVE-2026-14673: PostgreSQL amcheck does not clear untrusted search path2026-08-11
• criticalCVE-2026-69836: Microsoft Entra ID Remote Code Execution Vulnerability2026-08-11
• mediumCVE-2026-53792: rsync < 3.5.0 Out-of-Bounds Read via Zero-Length Checksum Block2026-08-11
• highCVE-2026-70347: Windows Installer Elevation of Privilege Vulnerability2026-08-11
• highCVE-2026-64909: Microsoft Office Remote Code Execution Vulnerability2026-08-11