Ubuntu vulnerabilities
Published CVEs affecting Ubuntu products: 6 record(s), with severity, exploitation and fixes.
CVE-2026-6862
Medium · 5.5
CWE-674 Apr 22, 2026
Efivar: efivar: denial of service due to stack overflow in device path node parsing
A flaw was found in libefiboot, a component of efivar. The device path node parser in libefiboot fails to validate that each node's Length field is at least 4 bytes, which is the minimum size for an EFI (Extensible Firmware Interface) device path node header. A local user could exploit this vulnerability by providing a specially crafted device path node. This can lead to infinite recursion, causing stack exhaustion and a process crash, resulting in a denial of service (DoS).
CVE-2026-3497
High · 7.5
CWE-908 Mar 12, 2026
Vulnerability in the OpenSSH GSSAPI delta included in various Linux distributions. This...
Vulnerability in the OpenSSH GSSAPI delta included in various Linux distributions. This vulnerability affects the GSSAPI patches added by various Linux distributions and does not affect the OpenSSH upstream project itself. The usage of sshpkt_disconnect() on an error, which does not terminate the process, allows an attacker to send an unexpected GSSAPI message type during the GSSAPI key exchange to the server, which will call the underlying function and continue the execution of the program without setting the related connection variables. As the variables are not initialized to NULL the code later accesses those uninitialized variables, accessing random memory, which could lead to undefined behavior. The recommended workaround is to use ssh_packet_disconnect() instead, which does terminate the process. The impact of the vulnerability depends heavily on the compiler flag hardening configuration.
CVE-2025-6966
Medium · 5.5
CWE-476 Dec 5, 2025
Null-pointer dereference in python-apt TagSection.keys()
NULL pointer dereference in TagSection.keys() in python-apt on APT-based Linux systems allows a local attacker to cause a denial of service (process crash) via a crafted deb822 file with a malformed non-UTF-8 key.
CVE-2025-7044
Medium · 6.5
CWE-269 Dec 3, 2025
Privilege Escalation in MAAS via Websocket Request Manipulation
An Improper Input Validation vulnerability exists in the user websocket handler of MAAS. An authenticated, unprivileged attacker can intercept a user.update websocket request and inject the is_superuser property set to true. The server improperly validates this input, allowing the attacker to self-promote to an administrator role. This results in full administrative control over the MAAS deployment.
CVE-2025-2486
High · 8.8
CWE-489 Nov 26, 2025
UEFI Shell accessible in AAVMF with Secure Boot enabled on Ubuntu
The Ubuntu edk2 UEFI firmware packages accidentally allowed the UEFI Shell to be accessed in Secure Boot environments, possibly allowing bypass of Secure Boot constraints. Versions 2024.05-2ubuntu0.3 and 2024.02-2ubuntu0.3 disable the Shell. Some previous versions inserted a secure-boot-based decision to continue running inside the Shell itself, which is believed to be sufficient to enforce Secure Boot restrictions. This is an additional repair on top of the incomplete fix for CVE-2023-48733.
CVE-2021-3493
High · 7.8
KEV Urgent · 74 Public exploit CWE-863 Apr 17, 2021
Linux Kernel Privilege Escalation Vulnerability
The overlayfs implementation in the linux kernel did not properly validate with respect to user namespaces the setting of file capabilities on files in an underlying file system. Due to the combination of unprivileged user namespaces along with a patch carried in the Ubuntu kernel to allow unprivileged overlay mounts, an attacker could use this to gain elevated privileges.