EUVD-2026-86296

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 MO...

CVE-2026-88361

SumatraPDF 3.6.1 contains an integer overflow vulnerability in EngineMupdf::BuildPageLabelRec when parsing PDF PageLabels /Nums entries...

PT-2026-97866

Name of the Vulnerable Software and Affected Versions SumatraPDF version 3.6.1 Description An integer overflow occurs in the EngineMupdf::BuildPageLabelRec function when the software parses PDF PageLabels /Nums entries. An integer overflow is a condition where an arithmetic operation attempts to...

CVE-2026-26054: Out-of-bounds Read

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 MO...

CVE-2026-88361: Integer Overflow or Wraparound

SumatraPDF 3.6.1 contains an integer overflow vulnerability in EngineMupdf::BuildPageLabelRec when parsing PDF PageLabels /Nums entries...

CVE-2026-88361

SumatraPDF 3.6.1 contains an integer overflow vulnerability in EngineMupdf::BuildPageLabelRec when parsing PDF PageLabels /Nums entries...

CVE-2026-88361

SumatraPDF 3.6.1 contains an integer overflow vulnerability in EngineMupdf::BuildPageLabelRec when parsing PDF PageLabels /Nums entries...

CVE-2026-88361

SumatraPDF 3.6.1 contains an integer overflow vulnerability in EngineMupdf::BuildPageLabelRec when parsing PDF PageLabels /Nums entries...

PT-2026-98141

Name of the Vulnerable Software and Affected Versions SumatraPDF versions prior to 3.6 Description The MobiDoc::ParseHeader function in src/MobiDoc.cpp validates records using kMobiHeaderMinLen, while DecodeMobiDocHeader creates a decoder sized for kMobiHeaderLen without verifying the actual...

CVE-2026-88361

SumatraPDF version 3.6.1 is vulnerable to an integer overflow within the EngineMupdf::BuildPageLabelRec() function. This vulnerability occurs when the software parses PDF PageLabels /Nums entries . The technical details do not specify a direct exploitation path or specific remote impact beyond th...

EUVD-2026-86287

SumatraPDF 3.6.1 contains an integer overflow vulnerability in EngineMupdf::BuildPageLabelRec when parsing PDF PageLabels /Nums entries...

SumatraPDF LZX Heap Buffer Overflow DoS

The vulnerability of the makeDecodeTable function in the ext/CHMLib/lzx.c file of the SumatraPDF program, which is used to display documents in formats such as PDF, EPUB, MOBI, FB2, CHM, XPS, and DjVu, relates to the execution of operations outside of the buffer. Exploiting this vulnerability cou...

CVE-2026-55586

SumatraPDF is a multi-format reader for Windows. In 3.6.1 and earlier, a crafted CHM file can supply malformed LZX Huffman code lengths to makedecodetable in ext/CHMLib/lzx.c. In the long-code branch, the function writes new internal nodes through nextsymbol before validating that the canonical...

EUVD-2026-63469

SumatraPDF is a multi-format reader for Windows. In 3.6.1 and earlier, a crafted CHM file can supply malformed LZX Huffman code lengths to makedecodetable in ext/CHMLib/lzx.c. In the long-code branch, the function writes new internal nodes through nextsymbol before validating that the canonical...

CVE-2026-55586 SumatraPDF: Heap out-of-bounds write in vendored CHMLib LZX Huffman table construction reachable from crafted CHM files

SumatraPDF is a multi-format reader for Windows. In 3.6.1 and earlier, a crafted CHM file can supply malformed LZX Huffman code lengths to makedecodetable in ext/CHMLib/lzx.c. In the long-code branch, the function writes new internal nodes through nextsymbol before validating that the canonical...

CVE-2026-55586 SumatraPDF: Heap out-of-bounds write in vendored CHMLib LZX Huffman table construction reachable from crafted CHM files

SumatraPDF is a multi-format reader for Windows. In 3.6.1 and earlier, a crafted CHM file can supply malformed LZX Huffman code lengths to makedecodetable in ext/CHMLib/lzx.c. In the long-code branch, the function writes new internal nodes through nextsymbol before validating that the canonical...

CVE-2026-55586 SumatraPDF: Heap out-of-bounds write in vendored CHMLib LZX Huffman table construction reachable from crafted CHM files

SumatraPDF is a multi-format reader for Windows. In 3.6.1 and earlier, a crafted CHM file can supply malformed LZX Huffman code lengths to makedecodetable in ext/CHMLib/lzx.c. In the long-code branch, the function writes new internal nodes through nextsymbol before validating that the canonical...

CVE-2026-55586

SumatraPDF 3.6.1 and earlier (Windows) contains a heap out-of-bounds write in the vendored CHMLib LZX decompressor. A crafted CHM file can supply malformed Huffman code lengths to make_decode_table in ext/CHMLib/lzx.c. In the long-code branch, internal nodes are written via next_symbol before val...

CVE-2026-55586: Improper Restriction of Operations within the Bounds of a Memory Buffer

SumatraPDF is a multi-format reader for Windows. In 3.6.1 and earlier, a crafted CHM file can supply malformed LZX Huffman code lengths to makedecodetable in ext/CHMLib/lzx.c. In the long-code branch, the function writes new internal nodes through nextsymbol before validating that the canonical...

PT-2026-79059

Name of the Vulnerable Software and Affected Versions SumatraPDF versions prior to 3.6.2 Description A crafted CHM file can provide malformed LZX Huffman code lengths to the make decode table function in ext/CHMLib/lzx.c. In the long-code branch, the function writes new internal nodes via next...