CVE-2026-107216: Excelize ANCHORARRAY: mutually-referencing array formulas recurse unboundedly via re-entrant CalcCellValue, causing a fatal stack overflow

ANCHORARRAY (calc.go:15137 on current master) evaluates each cell of the referenced spill range by calling the exported CalcCellValue, which unconditionally constructs a fresh calcContext — fresh entry marker, fresh iterations map, full MaxCalcIterations budget (calc.go:896-900). The circular-reference control only exists within one context: the entry-exclusion marker and per-ref iteration budget are fields of that single context, and completion-based caching (formulaArgCache/calcRawCache) only ever stores results of evaluations that finish.

During a pure cycle no nested evaluation ever finishes, so nothing is ever cached to break the recursion, and each hop re-arms the entire budget. Two ordinary, Excel-legal constructs in an attacker-supplied workbook are enough:

• A1 (dynamic array formula, ref A1:A1): _xlfn.ANCHORARRAY($B$1)
• B1 (dynamic array formula, ref B1:B1): _xlfn.ANCHORARRAY($A$1)

→ CalcCellValue → calcCellValue → evalInfixExp → parseReference → cellResolver → … → ANCHORARRAY → CalcCellValue → … forever, ending in a fatal, unrecoverable Go runtime error: runtime: goroutine stack exceeds …-byte limit / fatal error: stack overflow. Go stack overflows cannot be recovered — the whole process aborts.