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Part of a story covered by 6 sources: “Linux kernel local privilege escalation wave: Copy Fail, ZcopyReaper and IPv6 use-after-free drive CERT-EU, Ubuntu and ZDI advisories” — merged summary and timeline →

USN-8728-1: Linux kernel (GCP) vulnerabilities

AI summary · glm-5.3-flash

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
VendorsUbuntu
ProductsLinux kernel
OrganizationsArmAMD

Vulnerabilities mentionedAll →

CVEVulnerabilityCVSSEPSSFlagsAffectedExposurePublished
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 & X1C,

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 & X1C, Cortex-A710, Cortex-A78, A78AE & A78C, Cortex-A77, Cortex-A76 & A76A may allow writes to resources owned by a higher exception level.

NVD description · AI analysis pending
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 diff

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 different privilege level, potentially resulting in privilege escalation.

NVD description · AI analysis pending
7.3<1%
Full 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. (CVE-2025-10263) It was discovered that some AMD Zen 2 processors did not properly isolate shared resources in the operation cache. A local attacker could possibly use this issue to corrupt instructions executed at a higher privilege level, resulting in privilege escalation. (CVE-2025-54518) Several security issues were discovered in…

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