SumatraPDF 3.7.0.22298 contains a signed integer overflow in LitParseHeader() that computes the offset hdrLen + nPieces * 16 without validating the result. If the sum overflows to a negative value, the subsequent pointer construction in LitU32() dereferences an invalid address, causing the application to terminate deterministically. No evidence exists of code execution or data leakage; the flaw merely disrupts availability.

The vulnerability affects the SumatraPDF reader (sumatrapdfreader:sumatrapdf) specifically in version 3.7.0.22298. No fixed or patched releases are listed in the current review, and the vendor has not yet provided an update path.

With a CVSS score of 5.5 the flaw is considered moderate and the EPSS score is not available. It is not listed in the CISA KEV catalog. The flaw is exploitable by an attacker who can supply a crafted LIT file to the application, which may be achieved through a local or remote file that the user opens or that the application retrieves over a network. Successful exploitation causes the program to crash; it does not provide remote code execution, data disclosure, or persistence. The risk is limited to service interruption for the affected user or system, but it can impact availability for multiple users if the application is broadly deployed.