Vulnerability · Published Oct 13, 2026 · Assigned by redhat

CVE-2026-88838Busybox: busybox: non-root mount option filter bypass allows clearing fstab security restrictions

Medium 5.5

In plain English

A medium-severity security flaw in Red Hat Hardened Images from Red Hat. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 1% of all known vulnerabilities).

Severity (CVSS 3.1)5.5Medium

Exploit odds (30 days)0.1%top 98.6% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

A flaw was found in BusyBox's mount utility. A non-root user can bypass mount security restrictions set in /etc/fstab by specifying clearing-mask options on the command line. These options pass the non-root flag filter and are merged with fstab options as strings; when the combined options are re-parsed, clearing options can override nosuid, nodev, and noexec protections the administrator intended to enforce.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Debian:12	busybox	no fix listed	DEBIAN-CVE-2026-88838
Debian:13	busybox	no fix listed	DEBIAN-CVE-2026-88838
Debian:14	busybox	no fix listed	DEBIAN-CVE-2026-88838
Ubuntu:22.04:LTS	busybox	no fix listed	UBUNTU-CVE-2026-88838
Ubuntu:24.04:LTS	busybox	no fix listed	UBUNTU-CVE-2026-88838
Ubuntu:26.04:LTS	busybox	no fix listed	UBUNTU-CVE-2026-88838
Ubuntu:26.10	busybox	no fix listed	UBUNTU-CVE-2026-88838

Affected products (as reported)

Vendor	Product	Versions
Red Hat	Red Hat Hardened Images	see references

Weakness: CWE-693 · Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

References

https://access.redhat.com/security/cve/CVE-2026-88838 vdb-entry, x_refsource_REDHAT
RHBZ#2531352 issue-tracking, x_refsource_REDHAT