Actively Exploited V8 Type Confusion in Google Chrome (CVE-2026-85046)
CISA: Google Chromium V8 Type Confusion Vulnerability
CVSS 3.1
8.8high
EPSS
1%p72
Published
()
KEV added
AI analysis
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.
What to 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.
Affected
Google Chrome
prior to 152.0.7977.82
Google Chromium V8
V8 engine versions bundled with Chrome prior to 152.0.7977.82
Estimated exposure
massmultiple billions of users/installs (Chrome is the dominant desktop browser at roughly 65% market share, with an estimated 3+ billion active users, plus… — Chrome's browser market share (~two-thirds of desktop usage) and multi-billion active-user base make this effectively universal exposure among desktop users, with additional exposure via other Chromium-derived browsers that embed the V8…
Order-of-magnitude estimate by the model from install counts, market share and public scan data it knows; verify before quoting.
Description
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. (Chromium security severity: High)
CISA Known Exploited Vulnerability
Affected
Google Chromium V8
Required action
Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
CISA added the actively exploited Chromium V8 type confusion zero-day CVE-2026-85046 to its KEV catalog, urging patching of Chrome, Edge, and Opera.
CISA added CVE-2026-85046, a V8 type confusion flaw (CWE-843) in Chromium-based browsers, to its Known Exploited Vulnerabilities catalog. A remote attacker can trigger arbitrary code execution inside the browser sandbox via a specially crafted HTML page. Google Chrome is directly affected, and Microsoft Edge, Opera, and other Chromium-based browsers may also be impacted depending on their V8 version. Google has released a Stable channel Chrome update, and CISA directs mitigations under Binding Operational Directive 26-04.
Google patched 12 Chrome flaws including in-the-wild V8 zero-day CVE-2026-85046; CISA added it to the KEV catalog.
Google released Chrome 152.0.7977.82/.83 for Windows and Mac (152.0.7977.82 for Linux) fixing 12 vulnerabilities, including CVE-2026-85046, a type confusion flaw in the V8 JavaScript engine being exploited in the wild. CISA added CVE-2026-85046 to its Known Exploited Vulnerabilities Catalog with a patch deadline of September 18, 2026. This is Chrome's sixth zero-day patched in 2026, following CVE-2026-2441, CVE-2026-3909, CVE-2026-3910, CVE-2026-5281 and CVE-2026-11645. The other 11 fixes include use-after-free, out-of-bounds, race condition and input validation flaws in Skia, WebGL, DevTools, Network, Compositing and other components.
Microsoft's record 974-CVE Patch Tuesday ships two exploited Windows zero-days, while Adobe's StyleSmuggler zero-day (CVE-2026-75650) gives unauthenticated RCE in Magento.
Microsoft's September Patch Tuesday addresses 974 CVEs, including two zero-days already under exploitation: CVE-2026-85880, a Windows ALPC privilege escalation leading to SYSTEM via sandbox escape, and CVE-2026-81963, a Windows Update Stack privilege escalation. Adobe patched 172 CVEs, including the max-severity StyleSmuggler zero-day CVE-2026-75650 in Magento and Adobe Commerce, which Sansec reports is being exploited since September 4 to inject PHP into templates and install a C2-connected backdoor. CISA added CVE-2026-85880, CVE-2026-81963, and CVE-2026-75650 to its Known Exploited Vulnerabilities Catalog with patch deadlines of September 22 and September 11. The piece also notes Google-patched Chrome V8 zero-day CVE-2026-85046 lacks a Microsoft advisory for Edge, and flags nine Exchange Server flaws including remote unauthenticated RCE CVE-2026-55007.
Proofpoint reports multiple espionage groups rapidly adopting BlueMoon, a new exploit kit chaining Chrome and Windows zero-days.
Proofpoint identified a new exploit kit, BlueMoon, chaining two Chrome V8 zero-days (CVE-2026-85046, CVE-2026-87491) with a Windows ALPC privilege escalation zero-day (CVE-2026-85880), all patched between September 3 and September 2026 Patch Tuesday. China-linked Violet Typhoon (APT31) first used it on August 28 against US NGOs and mining/commodity trading firms; UNK_LateNight, UNK_DoubleCheck, and UNK_QuietRacket adopted it within days against targets in the US, Vietnam, Indonesia, and Singapore. The kit exploits the V8 defects for sandbox escape, fingerprints the host, and injects a CreateProcess stub into the Chrome broker process to download and execute a payload via curl. Development artifacts suggest the kit's creators may have used AI to build it, potentially lowering the barrier to exploit development.
At least four China-aligned espionage groups chained three zero-days in Chromium browsers and Windows ALPC for espionage since late August.
Proofpoint observed at least four state-aligned threat groups, starting with TA412/Violet Typhoon/APT31 on August 28, chaining three zero-days in the 'BlueMoon' exploit chain targeting Chrome, Chromium-based browsers and Microsoft Windows. The chain includes RCE flaws in Chromium's JavaScript engine (CVE-2026-85046, CVE-2026-87491) and a Windows Advanced Local Procedure Call privilege-escalation zero-day (CVE-2026-85880), enabling sandbox code execution, sandbox escape and system privileges. APT31 delivered the chain via phishing links to NGOs, mining and commodity trading firms in the US, installing a browser extension disguised as Google Gemini to surveil activity and steal credentials. Other groups (UNK_LateNight, UNK_DoubleCheck, UNK_QuietRacket) targeted US aerospace, Vietnamese manufacturing, and Indonesian and Singaporean organizations; fewer than 20 victims were directly observed but the true count is likely higher.
Microsoft's September 2026 Patch Tuesday fixes 999 CVEs, a record, with two zero-day privilege escalation flaws already exploited in the wild.
Microsoft published 974 own-product vulnerabilities plus 25 non-Microsoft CVEs, totaling 999 — the most CVEs Microsoft has ever released in a single day. Two flaws are exploited in the wild: CVE-2026-85880, an out-of-bounds write in Windows ALPC granting SYSTEM privileges, and CVE-2026-81963, an improper link resolution flaw in the Windows Update Stack also leading to SYSTEM. Chrome's V8 zero-day CVE-2026-85046 was patched in Edge on September 2, but Microsoft had not published a corresponding advisory, leaving uncertainty about other Chromium fixes in Edge. October 14 lifecycle changes end servicing for Windows 11 24H2 Home/Pro, Office 2021, and Exchange Server 2016/2019.
Google patches actively exploited Chrome V8 zero-day CVE-2026-85046 (CVSS 8.8); CISA adds it to KEV with a September 18 deadline.
Google fixed 12 Chrome vulnerabilities, including CVE-2026-85046, a high-severity (CVSS 8.8) type confusion bug in the V8 JavaScript and WebAssembly engine. The flaw, reported by researcher Salvatore Gulizia on August 4, 2026, allows remote arbitrary code execution inside the browser sandbox via a crafted HTML page. Google confirmed the exploit exists in the wild, and CISA added the CVE to its KEV catalog, requiring Federal Civilian Executive Branch agencies to patch by September 18, 2026. This is the sixth actively exploited Chrome zero-day patched in 2026.
Multiple espionage actors, mostly China-nexus, are chaining Chrome V8 and Windows kernel zero-days (CVE-2026-85046, CVE-2026-85880) via the BlueMoon exploit kit against government and defense targets.
Proofpoint identified a new exploit kit dubbed BlueMoon chaining a Chromium V8 type-confusion RCE (CVE-2026-85046), a V8 sandbox escape, and a Windows kernel LPE (CVE-2026-85880). At least four distinct threat clusters, most with suspected China nexus, adopted the kit within days starting with TA412 (Violet Typhoon/APT31) on August 28, 2026. Both Chrome-side flaws were patch-gap zero-days with roughly a four-week exploitation window; the Windows LPE only works on Windows 10 and Server 2019/2022. TA412 used spearphishing posing as university interns to deliver the GemStone browser backdoor disguised as a Google Gemini extension; other clusters delivered ShadowPad via DLL sideloading and a Rust loader against targets in aerospace, government, and finance.
Two China-linked APT groups reused identical Chrome/Windows zero-day chain against NGOs, deploying GRIMWIDGE backdoor and LONGTALE credential-stealing extension.
Volexity reports that China-linked actors UTA0560 and JungleBamboo (APT31/TA412) ran byte-identical Chrome/Windows exploit chains against NGOs starting September 1, 2026, combining Chrome type confusion CVE-2026-85046, WebAssembly sandbox escape CVE-2026-87491, and Windows kernel flaw CVE-2026-85880. The Chrome bug was fixed in Chromium source but not yet shipped to Chrome users, making it an effective zero-day with an unusual patch gap. UTA0560 delivered the in-memory GRIMWEDGE JScript backdoor, while JungleBamboo deployed the SUPERSTOMP loader installing LONGTALE, a malicious Chrome extension disguised as Google Gemini that steals cookies, session tokens, and keystrokes. Volexity assesses with low confidence the exploit chain was sold or shared among different Chinese end-users.
Volexity attributes spear-phishing campaign exploiting Chrome-Windows zero-day chain to Chinese actors UTA0560 and APT31 deploying GRIMWEDGE and LONGTALE.
Volexity attributes a September 1, 2026 spear-phishing campaign targeting NGOs to China-linked UTA0560, which abused a reflected XSS flaw on a US university website to trigger a three-part exploit chain (CVE-2026-85046, CVE-2026-87491, CVE-2026-85880) escaping the Chrome V8 and browser sandboxes to deploy the GRIMWEDGE JavaScript backdoor with reconnaissance, file management, and command execution capabilities. The same chain was used near-simultaneously by JungleBamboo (APT31) to deploy SUPERSTOMP, installing the LONGTALE/GemStone credential-stealing Chrome extension masquerading as Google Gemini. The Chrome flaws were patched in Chromium but not yet in stable Chrome, creating an unusual patch-gap zero-day window attackers raced to exploit.
Volexity reports China-linked UTA0560 and JungleBamboo chained Chrome zero-day CVE-2026-85046 with kernel flaws to spy on NGOs.
Volexity documented campaigns detected on September 1, 2026, in which China-linked actors UTA0560 and JungleBamboo (APT31) chained CVE-2026-85046 (V8 type confusion), CVE-2026-87491 (WebAssembly sandbox escape), and CVE-2026-85880 (Windows kernel privilege escalation in RtlpCreateServerAcl). Victims were lured via links on legitimate U.S. university sites vulnerable to reflected XSS, then served hidden exploit iframes behind a donation-form image. Although a V8 fix had landed in Chromium's source after private August reporting, Chrome had not yet shipped it, creating a patch gap the actors exploited. The two groups installed distinct payloads: UTA0560 delivered the GRIMWEDGE JScript backdoor via DLL side-loading, while JungleBamboo used the SUPERSTOMP loader to install the LONGTALE credential-stealing Chrome extension disguised as Google Gemini.
Multiple China-linked espionage groups share the BlueMoon exploit kit chaining Chrome V8 zero-days and a Windows ALPC LPE to deploy backdoors.
Proofpoint and Volexity report that multiple espionage clusters share the BlueMoon exploit kit, chaining Chrome V8 zero-days CVE-2026-85046 and CVE-2026-87491 with the Windows ALPC local privilege escalation CVE-2026-85880. Proofpoint observed spearphishing use since August 28 by JungleBamboo (APT31), while Volexity saw UTA0560 targeting NGOs from September 1; UNK_LateNight hit US aerospace/defense with ShadowPad and UNK_DoubleCheck targeted Vietnamese manufacturers. The kit's maintainers reverse-engineer public Chromium fixes before stable Chrome releases, and Proofpoint suspects the ALPC exploit has existed since 2025.
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.
Proofpoint tracked an exploit kit dubbed BlueMoon that chains CVE-2026-85046, a Chrome V8 type-confusion bug, with an unnamed V8 sandbox escape and CVE-2026-85880, a Windows kernel privilege escalation using ALPC and the Windows Notification Facility. The first observed use was by China-nexus TA412 (APT31, Violet Typhoon, JungleBamboo) on August 28, 2026 against US NGOs, mining companies, and commodity trading firms, followed by UNK_LateNight targeting US aerospace and defense companies on September 2. Both V8 bugs were patch-gap zero-days: the fix was committed to Chromium on August 7 but reached stable Chrome on September 3, enabling rapid weaponization from public patches. TA412's post-exploitation payload, GemStone, is a malicious browser extension posing as an AI-powered Google Gemini companion that captures keystrokes, cookies, screenshots, and browsing history via a Cloudflare Worker C2.
Proofpoint reports the BlueMoon exploit kit, chaining two Chrome V8 zero-days and a Windows ALPC bug, being shared across China-linked espionage groups.
Proofpoint identified a new exploit kit, BlueMoon, first observed on August 28 and used by TA412 (APT31/Violet Typhoon) against US NGOs, mining firms, and commodity trading companies. The kit chains a V8 type confusion RCE (CVE-2026-85046), a V8 sandbox escape, and a Windows Advanced Local Procedure Call privilege escalation (CVE-2026-85880), both patched flaws having been exploited in the wild. At least four espionage groups, most with suspected China nexus including UNK_LateNight, adopted the kit within days, targeting US aerospace firms with defense-sector lures. Fewer than 20 organizations were observed targeted, and researchers believe AI-assisted exploit development against upstream Chromium patches enabled the kit's rapid creation and sharing.
Four China-aligned espionage groups, starting with TA412/APT31, chained zero-days CVE-2026-85046, CVE-2026-87491 and CVE-2026-85880 to spy on targets since late August.
TA412 (Violet Typhoon/APT31) began exploiting the BlueMoon chain on Aug. 28, followed by UNK_LateNight (US aerospace, Sept. 2), UNK_DoubleCheck (Vietnamese manufacturing via a compromised Southeast Asian government account) and UNK_QuietRacket (Indonesia and Singapore government, consulting and finance, Sept. 3). The chain pairs Chromium JavaScript engine RCE flaws CVE-2026-85046 and CVE-2026-87491 with the Windows ALPC privilege-escalation zero-day CVE-2026-85880, enabling sandbox escape and system privileges. Delivery used phishing links installing a fake Google Gemini browser extension that surveilled browser activity and stole credentials; Proofpoint directly observed fewer than 20 organizations but expects wider proliferation as the kit spreads.
Google patched 230 Chrome flaws in version 153.0.8010.36, including actively exploited V8 out-of-bounds write CVE-2026-87491 (CVSS 8.8), the seventh 2026 Chrome zero-day.
Google released Chrome 153.0.8010.36 on Linux and 153.0.8010.36/.37 on Windows and Mac, fixing 230 security vulnerabilities. CVE-2026-87491, an out-of-bounds write in the V8 JavaScript and WebAssembly engine (CVSS 8.8), is being exploited in the wild through specially crafted HTML pages to execute arbitrary code inside Chrome's sandbox. Google says it is the seventh actively exploited Chrome zero-day of 2026, following CVE-2026-2441, CVE-2026-3909, CVE-2026-3910, CVE-2026-5281, CVE-2026-11645, and CVE-2026-85046. Researcher Jihyeon Jeong of Seoul National University reported it on 2026-08-06 and received a $2,500 bounty; Google disclosed no technical details or attribution.
Google patches actively exploited Chrome zero-day CVE-2026-85046, a V8 type confusion bug enabling sandboxed code execution via crafted HTML pages.
Google patched 12 Chrome vulnerabilities, including CVE-2026-85046, a CVSS 8.8 type confusion flaw in the V8 JavaScript and WebAssembly engine exploited in the wild. The bug, reported by researcher Salvatore Gulizia (Serotav) on August 4, 2026, allows arbitrary code execution inside the sandbox via a crafted HTML page; the researcher described it as a V8 compiler bug enabling arbitrary read/write on the JavaScript heap. Fixes shipped in Chrome 152.0.7977.82/.83 for Windows and macOS and 152.0.7977.82 for Linux, and this is the sixth Chrome zero-day Google has fixed in 2026.
CISA added actively exploited Chromium V8 type confusion CVE-2026-85046 to the KEV catalog, requiring federal mitigation by September 18.
CISA added CVE-2026-85046, a type confusion vulnerability in Google Chromium's V8 JavaScript engine, to the Known Exploited Vulnerabilities catalog. The flaw allows a remote attacker to execute arbitrary code inside the browser sandbox via a crafted HTML page and affects Chromium-based browsers including Google Chrome, Microsoft Edge, and Opera. Federal agencies must apply vendor mitigations by 2026-09-18 under BOD 26-04; CISA notes known ransomware campaign use is currently unknown.
Google patched 26 Chrome flaws, including two critical use-after-frees and an actively exploited V8 sandbox escape (CVE-2026-85046); update to 152.0.7977.82/.83.
Chrome's desktop update fixes 26 security issues, including critical use-after-free flaws CVE-2026-84353 in Shared Tab Groups and CVE-2026-84352 in WebGL, both allowing code execution outside the browser sandbox via crafted HTML pages. Google subsequently patched CVE-2026-85046, a high-severity V8 JavaScript engine flaw with exploits already in the wild that enables arbitrary code execution inside the Chrome sandbox; HKCERT rates the overall risk as extremely high. Fixed versions are 152.0.7977.82/.83 on Windows and Mac and 152.0.7977.82 on Linux.
Google patched 12 Chrome flaws including actively exploited V8 type confusion zero-day CVE-2026-85046 (CVSS 8.8), enabling sandboxed remote code execution via crafted webpages.
Google released Chrome Stable 152.0.7977.82/.83 for Windows and Mac and 152.0.7977.82 for Linux, fixing 12 vulnerabilities including CVE-2026-85046, a type confusion in V8 with a CVSS score of 8.8. Google says an exploit exists in the wild, making this the sixth actively exploited Chrome zero-day of 2026. The bug affects the JavaScript and WebAssembly engine and allows arbitrary code execution inside the browser sandbox via a specially crafted HTML page. Researcher Salvatore Gulizia (Serotav) reported the flaw on August 4, 2026 and received a $1,000 bounty.