Threats & Adversaries · APT / Espionage

UTA0565 broadens Chrome zero-day delivery

On day 18, Volexity said a third Chinese actor, UTA0565, joined the campaign using the same Google Chrome CVE-2026-85046 and CVE-2026-87491 flaws and the Microsoft Windows CVE-2026-85880 flaw, but delivered them through multiple fake websites and phishing emails. The vulnerabilities were still unpatched when UTA0565 used them on September 3-4.

The lure works by sending victims to a spoofed site that looks like a real news or advocacy page, then quietly loading hidden content inside the page. That hidden load triggers the exploit chain, so the attack can land without the victim doing anything more than opening the link.

The shift matters because takedowns aimed at one domain no longer meaningfully end the campaign. If an organization leans on URL filtering or single-site removal, the exposure now sits in a distributed lure set: one fake site can go dark while another keeps the same chain alive.

16 sources · Sep 23

CVE-2026-85046

NVD KEV

Known exploited · CISA KEV

CVSS 8.8 HIGH: type confusion in V8 in Google Chrome prior to 152.0.7977.82 allowed a remote attacker to execute arbitrary code inside the sandbox via a crafted HTML page. Microsoft patch: Release Notes.

CISA federal remediation date Sep 18 · date passed

CVE-2026-85880

NVD KEV

Known exploited · CISA KEV

CVSS 7.8 HIGH: heap-based buffer overflow in Windows ALPC allows an authorized attacker to elevate privileges locally. Microsoft patch: 5122876.

Patch available KB5122876 Download →

CISA federal remediation date Sep 22 · date passed

CVE-2026-87491

NVD KEV

Known exploited · CISA KEV

Microsoft patch: Release Notes.

CISA federal remediation date Sep 23

Timeline

Sources

Vendor digest: Microsoft

Part of the PlainSec briefing for 2026-09-09

Every edition of this story: UTA0565 broadens Chrome zero-day delivery

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