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Isolated-vm Flaw Lets Sandboxed JavaScript Escape to Host for Potential RCE

Critical type-confusion flaw in isolated-vm Node.js sandbox (GHSA-864f-rcv7-6rh4) enables guest-to-host escape and potential RCE; fixed in 6.2.0 and 7.0.1.

Endor Labs researcher Cristian-Alexandru Staicu found a type confusion in the ExternalCopy component's handling of the transferList option in isolated-vm, letting sandboxed JavaScript corrupt host-process memory and escalate from controlled-address crashes to full control-flow hijack of the host, i.e., potential remote code execution. The flaw, tracked as GHSA-864f-rcv7-6rh4 with no CVE yet, affects all versions through 7.0.0 of the library, which sees nearly 1 million npm downloads weekly. It was patched in versions 6.2.0 and 7.0.1 released earlier in August 2026, and full exploit details are withheld to prevent attacks. The V8 Isolate boundary itself held; the failure was in the C++ marshalling code bridging host and guest.

The Hacker News · 26d agoVulnerability

Telegram Desktop Flaw Lets Hidden JavaScript Exfiltrate Messages From HTML Exports

Telegram Desktop HTML export XSS (CVSS 8.2) let bot messages exfiltrate exported chats; fixed in 7.0.1 but old exports stay vulnerable.

ExPatch researchers found that Telegram Desktop versions 4.15.1 (March 2024) through 6.9.3 wrote bot inline-keyboard button text into HTML chat exports without escaping, allowing a bot to plant invisible JavaScript. When a user opened the export in a browser, the script could exfiltrate every message in that 1,000-message file, rewrite the displayed content, or fake a verification form. The flaw (rated CVSS 3.1 8.2) was fixed by commit 8457d13a in 6.9.4 beta (July 3, 2026) and 7.0.1 stable (July 14, 2026), but pre-fix exports remain dangerous since updating the app does not fix old files. No CVE identifier or Telegram security advisory exists, and no exploitation in the wild is claimed.

The Hacker Newsupdated · 1d agofirst · 1d agoVulnerability 2 sources1