SumatraPDF: Heap out-of-bounds read in MOBI header parser.
SumatraPDF is a multi-format reader for Windows. Prior to 3.6, the MobiDoc::ParseHeader function in src/MobiDoc.cpp validates a record using kMobiHeaderMinLen but DecodeMobiDocHeader constructs a decoder sized for kMobiHeaderLen without receiving the actual remaining buffer length. A malformed MOBI file can use an attacker-controlled header length to bypass optional-field early returns and cause the decoder to read beyond a short heap buffer. Opening the crafted document can crash SumatraPDF. This issue is fixed in version 3.6.
CVE-2026-26054
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-26054
sumatrapdf
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"vendor": "sumatrapdfreader",
"product": "sumatrapdf",
"versions": [
{
"status": "affected",
"version": "< 3.6"
}
]
}
]- Related CVEs
- CVE-2026-26054
Source reference:
/cveMetadata/cveId
Publisher severity
medium
Source reference: /containers/cna/metrics
- Event
- #3164 · Revision 1
- Added to Heist Feed
- Publisher date