CVE-2026-23951 — SumatraPDF's Integer Underflow in PalmDbReader Leads to Crash
SumatraPDF is a multi-format reader for Windows. All versions contain an off-by-one error in the validation code that only triggers with exactly 2 records, causing an integer un…
Published: 2026-01-22 · CVSS: 5.5 · CVSS 3.1
SumatraPDF is a multi-format reader for Windows. All versions contain an off-by-one error in the validation code that only triggers with exactly 2 records, causing an integer underflow in the size calculation. This bug exists in PalmDbReader::GetRecord when opening a crafted Mobi file, resulting in an out-of-bounds heap read that crashes the app. There are no published fixes at the time of publication.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7