Ubuntu Linux EUVD-2026-32988

Attacker must have a local unprivileged shell account on an Ubuntu host running kernel 6.8, 6.17, or 7.0 with Canonical's AppArmor SAUCE patches present (i.e. a stock Ubuntu kernel, not a vanilla upstream build). The vulnerable path is reached only through AppArmor's notification handling, which requires AppArmor to be enabled and at least one profile that produces notifications to userspace (the typical Ubuntu default has AppArmor enabled). Limiting factors: PR:L means a local account is required so purely remote attackers cannot reach this without first landing code execution; UI:N means no victim interaction is needed once the attacker has a shell; stock upstream kernels and non-Ubuntu distributions without the SAUCE patches are not exposed.

The CVSS 3.1 vector AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H indicates local access with low privileges (any unprivileged user) is sufficient, no user interaction, and high impact across confidentiality, integrity, and availability - yielding 7.8. EPSS data was not provided and the CVE is not on CISA KEV, with no public exploit identified at time of analysis, so real-world urgency is moderate rather than emergency. The CIA=High triplet is somewhat aspirational for an OOB-read primitive: in practice OOB reads usually drive information disclosure or feed secondary exploitation rather than direct integrity/availability compromise, so the I/A ratings should be read as 'possible via the corrupted DFA state' rather than confirmed RCE. This is a meaningful local privilege/security-boundary issue on multi-tenant Ubuntu hosts (shared dev boxes, container hosts, CI runners) but a lower priority for single-user endpoints. Description and CVSS are consistent (both indicate local, low-priv, unprivileged-triggerable); no obvious conflict in the data.

A low-privilege user on a shared Ubuntu host - for example a CI runner, university lab box, or multi-tenant container host - triggers an AppArmor policy decision that requires userspace notification (such as opening a file mediated by a profile with prompting enabled), causing the SAUCE notification code to read past its buffer. The attacker observes the resulting DFA processing of out-of-bounds bytes to leak adjacent kernel heap contents or to destabilize policy evaluation, potentially weakening confinement of other workloads. No public exploit identified at time of analysis, so this scenario is theoretical based on the bug class.