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CVE-2026-87491 is an out-of-bounds write vulnerability in Google Chrome's V8 engine affecting versions before 153.0.8010.36. A remote attacker can trigger arbitrary code execution inside the Chrome sandbox through a crafted HTML page. BlueMoon exploitation uses a WebAssembly defect to corrupt metadata and replace compiled function code, bypassing the V8 sandbox after initial exploitation of CVE-2026-85046. The V8 sandbox escape is distinct from escaping Chrome's renderer sandbox, which the observed chain accomplishes using Windows kernel vulnerability CVE-2026-85880. Exploitation was observed while upstream fixes were public but had not yet reached stable browser releases.
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2 valid exploits after Mallory filtered fakes, detection scripts, and README-only repos.
This is a standalone eight-file Chrome exploit chain and Linux validation harness, not a framework module. stage1.js implements the CVE-2026-85046 V8 Float64Array corruption primitive, producing cage-relative 32-bit read/write and object-address primitives. poc.js builds custom WebAssembly modules, abuses exception handling/forged getters to extend the primitive, discovers renderer code aliases, and writes embedded x86-64 code that changes memory protections and patches memcpy GOT entries, reporting FULL_RW on success. retarget-loader.js dynamically fetches and instruments poc.js, then creates a sandboxed iframe targeting /STAGE2_C. After renderer-stage completion it enables a user-facing button. retarget-receiver.js receives the iframe message and assigns its source window to a mailto URI, attempting to carry/misattribute the user activation and invoke Evolution externally. run.py serves the stages on an ephemeral localhost port, launches specific vulnerable/fixed Chrome artifact versions via Selenium, monitors /proc and process activity for xdg-open/Evolution, and compares vulnerable versus fixed behavior. The payload is operational but heavily version-specific and uses hard-coded layout assumptions, addresses, native code, and external-handler expectations.
This three-file browser exploit repository contains a README, an HTML launcher, and a 5 KB JavaScript PoC. run.html loads an external CVE-2026-85046 exploit bootstrap followed by poc.js; the bootstrap is not included in this repository, so the provided PoC is a second-stage/chained exploit rather than a standalone reproduction. poc.js programmatically constructs two WebAssembly modules and relies on the external primitive for heap-address and V8-cage memory manipulation. The chain creates WebAssembly instances sharing an imported function table and tag, forges an exception-related getter by copying a private exception key, and repeatedly invokes a driver function to encourage optimization. The getter changes a table entry while optimized code assumes no relevant side effects. This preserves instance A's stale implicit metadata while dispatching to instance D. Instance D uses memory index 6, which the exploit asserts aliases instance A's executable Wasm jump-table/code region. The resulting arbitrary read/write wrappers (arwRead/arwWrite) alter compiled Wasm instructions. main() patches a compiled Wasm body to execute getpid, adjusts a displacement, and then runPayload() overwrites the same body with hard-coded Linux x86-64 code that performs write(1, "PWNED 2026\\n", 11). Success is shown in the page and console as RAW_NATIVE data. The README identifies CVE-2026-85046 and CVE-2026-87491 and claims the target is Chrome 152.0.7977.75. No remote network service, C2 host, IP address, or HTTP API is contacted by the exploit; execution is entirely local to a victim browser renderer.
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146 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
A Chrome V8 vulnerability described as enabling sandbox escape in BlueMoon Exploit Kit's exploitation chain. The kit was observed in espionage-focused campaigns delivering GemStone, ShadowPad, and unnamed malware.
A V8 sandbox-escape vulnerability used as the second stage of BlueMoon's exploit chain. After obtaining memory access through CVE-2026-85046, the kit corrupts WebAssembly metadata and substitutes shellcode for compiled function code. The shellcode reflectively loads a host-profiling DLL. Execution remains within the browser renderer process; the subsequent Windows kernel exploit enables the final broker-process injection.
A Chrome V8 WebAssembly sandbox-escape vulnerability reportedly chained with two other zero-days to compromise victims through spear-phishing links and browser exploitation.
Critical Google Chromium V8 vulnerability with potential for arbitrary code execution by a remote attacker. It is listed in CISA's Known Exploited Vulnerabilities catalog.
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Cross-references every affected SKU, including bundled OEM variants.
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