Unity Linux 20.1060a / 20.1070a Security Update: kernel (UTSA-2026-003163)

The Unity Linux 20 host has a package installed that is affected by a vulnerability as referenced in the UTSA-2026-003163 advisory. In the Linux kernel 4.15.x through 4.19.x before 4.19.2, mapwrite in kernel/usernamespace.c allows privilege escalation because it mishandles nested user namespaces...

Unity Linux 20.1070e Security Update: kernel (UTSA-2026-000347)

The Unity Linux 20 host has a package installed that is affected by a vulnerability as referenced in the UTSA-2026-000347 advisory. In the Linux kernel 4.15.x through 4.19.x before 4.19.2, mapwrite in kernel/usernamespace.c allows privilege escalation because it mishandles nested user namespaces...

USN-3836-2 linux-hwe, linux-gcp vulnerabilities

USN-3836-1 fixed vulnerabilities in the Linux kernel for Ubuntu 18.04 LTS. This update provides the corresponding updates for the Linux Hardware Enablement HWE kernel from Ubuntu 18.04 LTS for Ubuntu 16.04 LTS. Jann Horn discovered that the Linux kernel mishandles mapping UID or GID ranges inside...

USN-3833-1 linux-aws vulnerabilities

Jann Horn discovered that the Linux kernel mishandles mapping UID or GID ranges inside nested user namespaces in some situations. A local attacker could use this to bypass access controls on resources outside the namespace. CVE-2018-18955 Philipp Wendler discovered that the overlayfs implementati...

USN-3832-1: Linux kernel (AWS) vulnerabilities

Jann Horn discovered that the procfs file system implementation in the Linux kernel did not properly restrict the ability to inspect the kernel stack of an arbitrary task. A local attacker could use this to expose sensitive information. CVE-2018-17972 Jann Horn discovered that the mremap system...

DEBIAN-CVE-2018-18955

In the Linux kernel 4.15.x through 4.19.x before 4.19.2, mapwrite in kernel/usernamespace.c allows privilege escalation because it mishandles nested user namespaces with more than 5 UID or GID ranges. A user who has CAPSYSADMIN in an affected user namespace can bypass access controls on resources...

UBUNTU-CVE-2018-18955

In the Linux kernel 4.15.x through 4.19.x before 4.19.2, mapwrite in kernel/usernamespace.c allows privilege escalation because it mishandles nested user namespaces with more than 5 UID or GID ranges. A user who has CAPSYSADMIN in an affected user namespace can bypass access controls on resources...

Linux - Broken uid/gid Mapping for Nested User Namespaces Exploit

Exploit for linux platform in category local exploits Linux - Broken uid/gid Mapping for Nested User Namespaces Exploit commit 6397fac4915a "userns: bump idmap limits to 340" increases the number of possible uid/gid mappings that a namespace can have from 5 to 340. This is implemented by switchin...