PT-2026-38989 · Linux · Linux Kernel

Published 2026-05-08 · Updated 2026-05-16 · CVE-2026-43338

Positive Technologies (AI Summary)

CVSS v3.1

5.5

Medium

Base vector

AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description An issue exists in the Btrfs file system where qgroup ioctls do not reserve sufficient space for transaction items. Instead, they perform a transaction join, which fails to reserve space for quota tree updates or delayed references generated during the update process. While the quota root typically utilizes the global block reserve, failing to reserve proper space can lead to a transaction abort due to insufficient space (-ENOSPC) when running delayed references, resulting in an abuse of the global block reserve.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Related Identifiers

CVE-2026-43338

Affected Products

Linux Kernel

References · 15

• https://osv.dev/vulnerability/UBUNTU-CVE-2026-43338 · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2026-43338 · Security Note
• https://security-tracker.debian.org/tracker/CVE-2026-43338 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-43338 · Security Note
• https://git.kernel.org/stable/c/f9a4e3015db1aeafbef407650eb8555445ca943e · Patch
• https://git.kernel.org/stable/c/cf930a651eef6f8d915bf0ccd60c2045974f870c · Patch
• https://osv.dev/vulnerability/BELL-CVE-2026-43338 · Vendor Advisory
• https://ubuntu.com/security/CVE-2026-43338 · Vendor Advisory
• https://osv.dev/vulnerability/DEBIAN-CVE-2026-43338 · Vendor Advisory
• https://git.kernel.org/stable/c/386f5e16a383101a68e195c806b4eedb233cd1d3 · Patch
• https://git.kernel.org/stable/c/bb6eb33c908edbbb4d92abdc0c6c87f21b4952e8 · Patch
• https://git.kernel.org/linus/f9a4e3015db1aeafbef407650eb8555445ca943e · Note
• https://docs.bell-sw.com/security/cves/CVE-2026-43338 · Note
• https://twitter.com/CVEnew/status/2052811044494479431 · Twitter Post
• https://twitter.com/windowsforum/status/2053777685520744494 · Twitter Post