USN-8728-1: Linux kernel (GCP) vulnerabilities
Ubuntu issued kernel security update USN-8728-1 for GCP kernels fixing Arm TLB and AMD Zen 2 privilege escalation flaws (CVE-2025-10263, CVE-2025-54518).
Ubuntu released USN-8728-1, a security update for the Linux kernel used on Google Cloud Platform images. It fixes CVE-2025-10263, where certain Arm processors complete broadcast TLB invalidation before memory writes are globally observed, allowing local attackers to bypass memory protections or escalate privileges, and CVE-2025-54518, an AMD Zen 2 operation cache isolation flaw that can corrupt higher-privilege instructions. The notice also corrects several other kernel security issues.
- Fixes Arm TLB invalidation flaw allowing memory-protection bypass (CVE-2025-10263)
- Fixes AMD Zen 2 operation cache flaw enabling privilege escalation (CVE-2025-54518)
- Applies to Ubuntu GCP kernel builds; administrators should update
- Vendors
- Ubuntu
- Products
- Linux kernel
Vulnerabilities mentioned
All| CVE | Vulnerability | CVSS | EPSS | Signals | Published |
|---|---|---|---|---|---|
| CVE-2025-10263 | Arm C1-Ultra, C1-Premium, Neoverse V3 & V3AE, Neoverse V2, Neoverse V1, Neoverse-N2, Neoverse-N1, Cortex-X925, Cortex-X4, Cortex-X3, Cortex-X2, Cortex-X1 &… | 9.1 | <1% | ||
| CVE-2025-54518 | Improper isolation of shared resources within the CPU operation cache on Zen 2-based products could allow an attacker to corrupt instructions executed at a… | 7.3 | <1% |
From the original article
It was discovered that some Arm processors could complete a broadcast translation lookaside buffer (TLB) invalidation before memory writes made through the invalidated translation were globally observed. A local attacker could possibly use this to write to memory after permission to do so had been revoked, bypassing memory protections or escalating privileges.
ubuntu.com
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