Nation-State Clusters Rapidly Adopted BlueMoon Chrome-Windows Zero-Day Exploit Kit; Related Flaws Added to CISA KEV
Proofpoint and Volexity report four espionage clusters, mostly China-nexus, adopted the BlueMoon exploit kit — chaining Chrome V8 zero-days CVE-2026-85046 and CVE-2026-87491 with Windows LPE CVE-2026-85880 — within 12 days of first use on August 28, 2026,…
Proofpoint, working with Google Threat Intelligence Group, Microsoft Threat Intelligence Center and Volexity, disclosed an exploit kit dubbed BlueMoon that chains two Chrome V8 zero-days — type confusion CVE-2026-85046 and a sandbox escape CVE-2026-87491 (GBHackers describes it as a WebAssembly sandbox escape) — with a Windows kernel privilege escalation CVE-2026-85880 that abuses ALPC and the Windows Notification Facility (in RtlpCreateServerAcl per Volexity). Delivered via spear phishing, the chain escapes the Chrome sandbox and yields full Windows admin privileges from a single click. A China-nexus actor first used BlueMoon on August 28, 2026 against a small number of US NGOs, mining companies and commodity trading firms using internship, conference and rapport-building lures. Four espionage clusters, mostly China-linked, adopted it within 12 days against targets in the US, Vietnam, Indonesia and Singapore, including aerospace, manufacturing, government and finance. Proofpoint names TA412 (APT31, also tracked as Violet Typhoon and JungleBamboo; first use August 28), UNK_LateNight (US aerospace and defense, September 2, deploying ShadowPad), UNK_DoubleCheck (Vietnamese manufacturers) and UNK_QuietRacket; Volexity separately reported UTA0560 targeting NGOs from September 1, and Security Affairs counts UTA0560 among the four clusters. UTA0560 lured victims via links on legitimate US university sites vulnerable to reflected XSS, serving hidden exploit iframes behind a donation-form image. Volexity found UTA0560 and JungleBamboo ran byte-identical exploit shellcode but different payloads: GRIMWEDGE, an in-memory JScript backdoor polling ocr.opusaccel[.]top, versus the SUPERSTOMP loader installing LONGTALE/GemStone, a fake Google Gemini Chrome extension stealing cookies, session tokens and keystrokes that bypasses profile-integrity checks via a legacy HMAC fallback. Volexity assesses with medium confidence per GBHackers (reported as low confidence by Security Affairs) that a shared exploit developer sold the chain. The kit weaponized a patch gap: V8 fixes were committed to Chromium on August 7 after private reporting but only reached stable Chrome on September 3 (Malwarebytes reports stable patches on September 3 and 8), while the Windows flaw was fixed in September Patch Tuesday; the kit maintainers reverse-engineer public Chromium fixes, and Proofpoint suspects the ALPC exploit has existed since 2025. Development artifacts (markdown handover documents,…
- BlueMoon chains Chrome V8 type confusion CVE-2026-85046, a V8 sandbox escape CVE-2026-87491 (described as a WebAssembly sandbox escape by GBHackers), and Windows kernel LPE CVE-2026-85880 (abuses ALPC and the Windows Notification Facility;…
- First observed use: August 28, 2026, by China-nexus TA412 (APT31, also tracked as Violet Typhoon and JungleBamboo) against US NGOs, mining companies and commodity trading firms via internship, conference and rapport-building spear phishing.
- Four espionage clusters adopted the kit within 12 days; Proofpoint names UNK_LateNight (US aerospace/defense, September 2, delivering ShadowPad), UNK_DoubleCheck (Vietnamese manufacturers) and UNK_QuietRacket; targets spanned the US,…
- Volexity: UTA0560 and JungleBamboo (APT31) ran byte-identical exploit shellcode but different payloads — GRIMWEDGE in-memory JScript backdoor polling C2 ocr.opusaccel[.]top versus SUPERSTOMP loader installing LONGTALE/GemStone, a fake…
- Volexity confidence the chain was sold or shared among Chinese operators: medium per GBHackers, low per Security Affairs — a source discrepancy.
- UTA0560 redirected victims via links on legitimate US university sites vulnerable to reflected XSS, serving hidden exploit iframes behind a donation-form image.
- Patch gap: V8 fixes committed to Chromium on August 7 after private August reporting but reached stable Chrome on September 3 (Malwarebytes reports stable patches September 3 and 8); Windows flaw fixed in September Patch Tuesday; kit…
- AI-assist clues (no conclusive evidence): markdown handover documents, V8CTF references, diagnostic logging and a curl-based default payload; Proofpoint suggests AI may have lowered the barrier to exploit-kit development; adoption was fast…
Coverage timelineoldest first · each row is one article
- · 7d agoFour Nation-State Actors Used the Same Chrome Zero-Day Exploit Kit Within 12 Days
Security Affairs· 85
Proofpoint reports four nation-state actors, mostly China-nexus, adopted the BlueMoon Chrome and Windows zero-day exploit kit within 12 days, targeting US organizations.
Vulnerabilities in this storyAll →
| CVE | Vulnerability | CVSS | EPSS | Flags | Affected | Exposure | Published |
|---|---|---|---|---|---|---|---|
| CVE-2026-71362 | Unauthenticated Privilege Escalation Flaw in Adobe Commerce (Magento) CVE-2026-71362 is an incorrect-authorization flaw (CWE-863) in Adobe Commerce, the e-commerce platform formerly known as Magento, in which authorization checks are applied incorrectly and can be bypassed. It is triggered over the network without authentication or user interaction, per the CVSS 3.1 vector (AV:N/AC:L/PR:N/UI:N). A successful attacker gains elevated access to sensitive resources — a privilege-escalation condition that Adobe's APSB26-92 advisory and press coverage describe as an account-takeover risk. Any organization running an unpatched Adobe Commerce/Magento deployment is affected; exact version ranges are listed in Adobe security bulletin APSB26-92. The flaw came under active attack shortly after public disclosure, and its EPSS score of 25.1% (98th percentile) signals a high likelihood of continued near-term exploitation. Do: Apply the fix released under Adobe advisory APSB26-92 immediately, prioritizing internet-facing Commerce/Magento instances, and check the bulletin for the exact patched version ranges for your deployment. Because exploitation requires no credentials or user interaction, review admin accounts, API integrations, and user/role assignments for unauthorized privilege changes, and restrict admin-panel and storefront API access where feasible. Monitor Adobe's advisory for indicators of compromise given confirmed in-the-wild exploitation. | 9.1 | 25% |
| mass≈200,000+ Magento/Adobe Commerce storefronts worldwide | ||
| CVE-2026-75650 | Unauthenticated Template Injection RCE in Adobe Commerce and Magento (CVE-2026-75650) Adobe Commerce and Magento (including Adobe Commerce B2B) contain an improper neutralization of special elements used in a template engine (CWE-1336), a template-injection flaw that permits arbitrary code execution in the context of the current user. The flaw is reachable over the network by unauthenticated attackers, requires no user interaction, and its changed scope (CVSS 3.1 S:C) means injected code executes beyond the vulnerable component, producing a maximum-severity (CVSS 10.0) remote code execution condition. A successful attacker gains arbitrary code execution on the storefront server; in the observed campaign, intruders installed a Rust backdoor and a PHP web shell (dubbed 'StyleSmuggler') on compromised servers. Any organization running an Adobe Commerce, Adobe Commerce B2B, or Magento storefront is in scope, with internet-facing e-commerce deployments most exposed. Exploitation is confirmed in the wild: the bug was abused as a zero-day before patching and was added to CISA's Known Exploited Vulnerabilities catalog on 2026-09-08. Do: Apply Adobe's released patches immediately per vendor instructions, prioritizing internet-facing Commerce/Magento storefronts, and ensure compliance with CISA BOD 26-04 timelines for KEV entries. Hunt for 'StyleSmuggler' indicators of compromise, including unexpected Rust backdoor binaries and PHP web shells on hosts, and review template/theme customizations for tampering. Exact fixed version numbers are not included in the available data, so consult Adobe's advisory for the correct patched release for your Commerce/Magento version line. | 10.0 | 2% | KEV PoC |
| massroughly 100,000-300,000 internet-facing storefronts | |
| CVE-2026-81963 +1 in the same advisory: …85880 | Local Privilege Escalation via Link Following in Windows Update Stack CVE-2026-81963 is a link-following flaw (CWE-59, improper link resolution before file access) in the Microsoft Windows Update Stack, in which the component fails to correctly resolve file links before opening them. A local attacker with low privileges can plant or manipulate a link (symlink/junction) that the privileged update stack follows during operation, redirecting its file access to an attacker-controlled target. The result is local privilege escalation — CVSS 3.1 rates this 7.8 (high) with high confidentiality, integrity, and availability impact — allowing an authorized local user or malware already on the machine to gain elevated rights. Affected products are Windows 11 23H2, 24H2, 25H2, and 26H1 and Windows Server 2025; any unpatched system on those versions is exposed to any local account holder. The flaw was fixed in Microsoft's record September 2026 Patch Tuesday (974 CVEs), was added to CISA's KEV on 2026-09-08 as one of two Windows zero-days reported as exploited in the wild, and has no known public PoC or confirmed ransomware use. Do: Immediately deploy the September 2026 Patch Tuesday cumulative updates to every Windows 11 23H2/24H2/25H2/26H1 and Windows Server 2025 host; as a KEV entry under BOD 26-04, prioritize internet-exposed and high-value assets, apply vendor mitigations (or discontinue use) where patching is delayed, and follow CISA's forensics triage requirements if compromise is suspected. Verify deployment via patch telemetry and review which local accounts can trigger update-stack activity on shared or multi-user systems. | 7.8 | <1% | KEV |
| masswell over 1,000,000 | |
| CVE-2026-85046 | Actively Exploited V8 Type Confusion in Google Chrome (CVE-2026-85046) Google Chrome versions prior to 152.0.7977.82 contain a type confusion flaw (CWE-843) in the V8 JavaScript engine, which mishandles object types during engine operations (public proof-of-concept writeups indicate it is reachable through array sorting and WebAssembly-related code paths). A remote attacker triggers the flaw simply by getting a user to open a crafted HTML page, with no privileges or authentication required. Successful exploitation lets the attacker execute arbitrary code inside the browser's sandbox, and public reporting shows it being chained with Windows zero-days (the 'BlueMoon' exploit kit) by Chinese espionage groups for broader compromise. Any user of an unpatched Chrome or another build embedding the affected V8 engine is exposed. The vulnerability is a zero-day that was actively exploited in the wild before patching, was added to CISA's KEV on 2026-09-04, and has five public proof-of-concept references. Do: Update Google Chrome to 152.0.7977.82 or later immediately, and apply the corresponding V8 fix in any Chromium-based browser in use. Federal agencies must apply mitigations in line with CISA BOD 26-04 and its cloud-services requirements, evaluating each asset's internet exposure. Because public reporting shows this flaw chained with Windows zero-days in 'BlueMoon' attacks, patch the related Windows vulnerabilities as well and hunt for signs of exploit-chain activity on high-exposure endpoints. | 8.8 | 1% | KEV PoC ×5 |
| massmultiple billions of users/installs (Chrome is the dominant desktop browser at roughly 65% market share, with an estimated 3+ billion active users, plus… | |
| CVE-2026-86218 | Pre-Auth Static Code Injection RCE in N-able N-central (Exploited in the Wild) CVE-2026-86218 is a static code injection flaw (CWE-96) in N-able's N-central on-premises remote monitoring and management (RMM) platform, carrying a maximum CVSS 4.0 score of 10.0. An unauthenticated, remote attacker triggers it by sending crafted network input to the N-central server that is improperly neutralized and persisted into application-managed code, which the server then executes — no privileges (PR:N) or user interaction (UI:N) are required. Successful exploitation yields full server compromise with high impact on confidentiality, integrity, and availability, and because N-central acts as the management hub for downstream customer endpoints, compromise can expose the entire managed estate. Any organization running an affected N-central release (before 2026.3.1.14) — primarily MSPs and corporate IT departments using N-able RMM — is affected. The flaw is confirmed exploited in the wild: N-able patched it as a zero-day, CISA added it to the KEV catalog on 2026-09-08, and it is the fourth N-central hotfix in five weeks, though no public PoC is known and ransomware use is unknown. Do: Upgrade N-central to 2026.3.1.14 or later (or apply N-able's hotfix) immediately, as the flaw is in CISA's KEV catalog and BOD 26-04 timelines apply to federal stakeholders. Until patched, remove direct internet exposure of the N-central server (restrict to VPN/management networks via firewall allowlists) since no authentication is needed for exploitation. Because in-the-wild exploitation is confirmed, review internet-facing N-central servers for indicators of compromise such as unexpected processes, unusual child processes of the web service, and new or suspicious accounts. | 10.0 | <1% | KEV PoC ×2 |
| large≈ tens of thousands of deployed/internet-exposed N-central servers (order of magnitude ~10k+), each managing many downstream customer endpoints | |
| CVE-2026-87491 | Actively Exploited Out-of-Bounds Write in Google Chrome V8 CVE-2026-87491 is an out-of-bounds write (CWE-787) in the V8 JavaScript engine in Google Chrome, fixed in Chrome 153.0.8010.36, which Google shipped alongside roughly 230 other security fixes. An attacker can trigger the flaw remotely by luring a user (user interaction required) into opening a crafted HTML page that corrupts memory in V8. Successful exploitation allows the attacker to execute arbitrary code inside the Chrome browser sandbox, which constrains but does not eliminate the impact. All Google Chrome users running versions prior to 153.0.8010.36 are affected; because the flaw resides in V8, CISA tracks it as 'Google Chromium V8', and other Chromium-based browsers may inherit the fix in their own updates. The flaw is being actively exploited in the wild — it is the seventh actively exploited Chrome zero-day of 2026 and was added to CISA's KEV catalog on 2026-09-09 — though no public proof-of-concept is known and ransomware use is unknown. Do: Update Google Chrome to 153.0.8010.36 or later immediately (open Help > About Google Chrome to force the update and relaunch), and verify the version on all endpoints. Also patch headless or automated Chrome deployments (CI runners, scrapers, kiosks, CDP-based tooling) that may lag auto-updates, and prioritize remediation per CISA KEV and BOD 26-04 requirements for federal systems. No public PoC is known and ransomware use is unknown, but confirmed in-the-wild exploitation warrants urgent patching. | 8.8 | <1% | KEV |
| massbillions of installations (Chrome's install base exceeds 3 billion users) |