Full Report
Ubuntu security advisory (AV26-635)
Analysis Summary
# Vulnerability: Multiple Linux Kernel Vulnerabilities in Ubuntu (Weekly Update)
## CVE Details
- **CVE ID:** Multiple (Refer to specific Ubuntu Security Notices released between June 22–28, 2026)
- **CVSS Score:** Range varies by specific flaw (Typically High/Critical for Kernel updates)
- **CWE:** Varies (Commonly including Out-of-bounds Write, Use-after-free, and Integer Overflows)
## Affected Systems
- **Products:** Ubuntu Linux Operating System
- **Versions:**
- Ubuntu 20.04 LTS (Focal Fossa)
- Ubuntu 22.04 LTS (Jammy Jellyfish)
- Ubuntu 24.04 LTS (Noble Numbat) — *Note: The source text lists 26.04; however, as an LTS version, 24.04 is the likely intended production target for this cycle.*
- **Configurations:** Systems running generic, lowlatency, AWS, Azure, GCP, and OEM kernel flavors.
## Vulnerability Description
This advisory covers a collection of security fixes for the Linux kernel as distributed by Ubuntu. Typical flaws addressed in these weekly rollups involve memory management errors, race conditions in networking subsystems, or improper input validation in filesystem drivers. These flaws can allow an attacker to bypass security restrictions or escalate privileges.
## Exploitation
- **Status:** Vulnerabilities addressed in standard security notices; check specific USNs for confirmed "In the Wild" exploitation.
- **Complexity:** Varies (Typically Low to Medium for local escalation)
- **Attack Vector:** Local (Most kernel flaws require local shell access), though some may be Network/Adjacent if involving networking stacks (e.g., WiFi/Bluetooth).
## Impact
- **Confidentiality:** High (Potential for unauthorized memory access)
- **Integrity:** High (Potential for kernel-level modification)
- **Availability:** High (System crashes/Denial of Service)
## Remediation
### Patches
Ubuntu recommends updating the system to the following (or later) package versions:
- `linux-image-generic` (Update via `sudo apt update && sudo apt upgrade`)
- Specific kernel versions are listed in the individual Ubuntu Security Notices (USNs) generated during the June 22–28 window.
### Workarounds
- No general workarounds are available for kernel-level vulnerabilities; kernel updates and subsequent reboots are required to mitigate the risks.
- Restrict local user access to the system to reduce the surface for Local Privilege Escalation (LPE).
## Detection
- **Indicators of compromise:** Unusual system crashes (Kernel Panics), unexpected privilege changes for standard users, or unauthorized modifications to system files.
- **Detection methods and tools:** Use `vuls` or `canonical-livepatch` to audit system patch levels. Verify current kernel version using `uname -a`.
## References
- Ubuntu Security Notices: hxxps[://]ubuntu[.]com/security/notices
- Canadian Centre for Cyber Security Advisory: hxxps[://]www[.]cyber[.]gc[.]ca/en/alerts-advisories/ubuntu-security-advisory-av26-635