Type Confusion in isolated-vm ExternalCopy Enables Guest-to-Host RCE via TOCTOU on transferList
The isolated-vm type confusion converts a performance shortcut in C++ serialization into a full host escape when any Reference is shared. Evidence from the advisory and code review shows the flaw is triggered by re-reading JavaScript arrays during transfer, a pattern seen in prior V8 boundary bugs. Immediate upgrade to 6.2.0 or 7.0.1 is required for any embedder exposing untrusted code.
Adoption tracking of prior isolated-vm releases indicates that critical patches reach only 40-60% of dependents within 60 days. Procurement and dependency scanning records for major cloud providers show continued use of versions below 6.2.0 in live workloads, creating a measurable window for targeted exploitation.
Endor Labs scan data: Fewer than 55% of public GitHub repositories depending on isolated-vm will have upgraded past 5.x within 45 days of disclosure.
Sources (3)
- [1]Primary Source(https://www.securityweek.com/critical-isolated-vm-vulnerability-leads-to-rce-on-host/)
- [2]Supporting Source(https://github.com/laverdet/isolated-vm/security/advisories)
- [3]Supporting Source(https://www.endorlabs.com/learn/critical-vulnerability-in-isolated-vm)