XBOW assembled a Chrome three-stage exploit chain with agent assistance

In this reported chain, a crafted page first reaches a V8 compiler assumption that incorrectly treats a mutable number object as reusable during deoptimization. A separate animated WebP issue moves control outside V8’s sandbox via inconsistent frame state. The last stage uses a Crashpad read/size boundary to cross from the renderer into a less restricted process. XBOW says human researchers directed and integrated parallel AI-assisted search and exploitation. The source makes claims about the controlled reproduction and reward; it does not document in-the-wild compromise. CVE identifiers should not be assigned to individual stages without checking Chromium records because the accompanying press text contains a mapping conflict.

The reported chain combined AI-assisted vulnerability work with human research direction and integration; it was not a confirmed autonomous attacker campaign.

A complete exploit chain does not imply each constituent bug can be triggered by itself. The reported sequence has separate renderer, privilege and sandbox prerequisites; patch and CVE statements should be checked against Chromium advisories for each stage.