CVE-2026-107733

SumatraPDF before version 3.6 has a vulnerability in the MobiDoc::ParseHeader function, where the decoder is sized for a fixed length rather than the actual buffer length. A malformed MOBI file can cause a read beyond a short heap buffer, leading to application crash.

SumatraPDF 3.6.1 and earlier embeds selected or pasted translation text in quoted Windows command lines in src/SelectionTranslate.cpp using incomplete quote-only escaping. The affected BuildGrokTranslateCmdLineTemp(), BuildClaudeTranslateCmdLineTemp(), and BuildCodexTranslateCmdLineTemp() functions can allow attacker-controlled text to inject model, working-directory, approval, or sandbox-bypass flags when the corresponding agentic CLI backend is installed and used.

SumatraPDF 3.6.1 and earlier has a vulnerability in ChmFile::GetCharZ() where file-controlled unsigned offsets are narrowed to signed integers without a lower-bound check. This can cause reads before the /#STRINGS buffer and deterministic application termination.

SumatraPDF 3.6.1 and earlier, and pre-release 3.7.0.20369 when WebView2 is absent, has a vulnerability in ParseProtoUrl() where the signed host component of an its:// URL is used as an index into gHtmlWindows. This can cause out-of-bounds pointer read and invalid callback dereference, terminating the process.

SumatraPDF 3.6.1 and earlier has a vulnerability in MaybeFlipBitmap() where GDI+ reads the attacker-controlled PropertyTagOrientation size into a fixed 64-byte stack buffer. Opening a crafted TIFF can overwrite stack control data, though tested builds terminate via stack cookie check.

SumatraPDF 3.6.1 and earlier has a vulnerability in InitializePolicies() where the sumatrapdfrestrict.ini path starts with gPolicyRestrictions set to Perm::All and only ORs permission bits, so the INI file never revokes permissions. Deploying with this INI file, including malformed or zero-valued settings, can silently bypass configured disk, network, printing, registry, clipboard, preference, and fullscreen restrictions.

SumatraPDF 3.5.2 and earlier substitutes an attacker-controlled SyncTeX source filename for the %f placeholder in an external editor command line without safe Windows argument quoting, and the resulting command line is passed to CreateProcessW(). A user with an external editor configured or auto-detected who opens a PDF with a crafted .synctex.gz file and invokes inverse search can inject command-line flags.

SumatraPDF 3.6.1 and earlier interpolates untrusted document paths and PDF link targets into notification text that ParseTip() interprets as trusted tip markup. When a user clicks an injected link, ExecuteTipLink() dispatches its CmdExec command and can execute an attacker-selected local program in the user's context.

SumatraPDF 3.7.0.22298 has four independently reachable range-validation variants in src/LitDoc.cpp that allow file-controlled offsets and sizes to overflow, narrow to negative values, or wrap before incomplete bounds checks. Opening a crafted LIT file can cause invalid pointer reads and deterministic application termination.

SumatraPDF 3.7.0.22298 has a vulnerability in LitParseHeader() in src/LitDoc.cpp where the attacker-controlled hdrLen + nPieces * 16 section offset is computed using signed 32-bit arithmetic without validating the complete result. When the aggregate calculation overflows to a negative value, pointer construction reaches an invalid read in LitU32(), causing deterministic application termination.