CVE-2026-26054Published

SumatraPDF: Heap out-of-bounds read in MOBI header parser.

Exact source revision recorded 23 Oct 2026 15:48:27 UTC. It does not establish the source's current position. Latest evidence.

Recorded JSON

cve-program · CVE-2026-26054

Published

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.

Source published: 24 Sep 2026 16:48:03 UTC
Source modified: 28 Sep 2026 15:33:32 UTC
Observed here: 23 Oct 2026 15:48:27 UTC
Source terms: CVE Program Terms of Use

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CVSS 4.0 · 6.8 CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N