CVE-2026-107730 SumatraPDF: Signed integer overflow in the LIT header parsing causes invalid-pointer read

SumatraPDF is a multi-format reader for Windows. In 3.7.0.22298, LitParseHeader in src/LitDoc.cpp computes the attacker-controlled hdrLen + nPieces 16 section offset using signed 32-bit arithmetic without validating the complete result. When the component values make that aggregate calculation...