CVE-2026-45893 Linux CVE debrief

Who should care

Linux system administrators running AppArmor, kernel maintainers, security teams monitoring kernel LSM (Linux Security Modules) vulnerabilities, and organizations deploying Linux on architectures with strict memory alignment requirements

Technical summary

The vulnerability exists in AppArmor's table creation code path where data blobs from userspace are processed. On architectures with strict alignment requirements, unaligned memory accesses can cause exceptions, data corruption, or undefined behavior. The fix implements optimized copying that ensures proper alignment during table construction from potentially unaligned source memory.

Defensive priority

medium

Recommended defensive actions

• Apply the relevant stable kernel patch for your kernel version
• Monitor kernel stable updates for AppArmor fixes
• Review AppArmor policy loading mechanisms for unaligned access patterns
• Validate kernel builds on architectures with strict alignment requirements (e.g., ARM, RISC-V, SPARC)
• Consider enabling kernel hardening features that detect or prevent unaligned access

Evidence notes

The CVE description and kernel commit messages confirm this is a fix for unaligned memory access in AppArmor table creation. The source blob may come from userspace, making alignment unpredictable. Four stable kernel commits are referenced, indicating backports to multiple kernel versions.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.