Medium · CVSS 6.8CVE-2026-107733

SumatraPDF: Null-pointer dereference in `CmdExec` when no document tab is openCVE-2026-107733

Answer in brief

CVE-2026-107733 records a Medium severity (CVSS 6.8) vulnerability in SumatraPDF: Null-pointer dereference in `CmdExec` when no document tab is open. The current sources do not mark it as known exploited. The current feed maps sumatrapdfreader/sumatrapdf (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Oct 8, 2026Updated Oct 8, 2026Source checked Oct 8, 2026First seen by HOL Oct 8, 2026Material review Oct 8, 2026

Upstream Advisory

Key facts

Risk: Medium · CVSS 6.8
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

CVSS is 6.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps sumatrapdfreader/sumatrapdf (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
sumatrapdfreader/sumatrapdfgeneric	<=3.6.1	= 3.6.1

Recommended response

Check inventory. Check lockfiles and deployed manifests for sumatrapdfreader/sumatrapdf.
Review the reported fix. Update sumatrapdfreader/sumatrapdf to = 3.6.1 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Oct 8, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Oct 8, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Oct 8, 2026

Sources and claim methodology

Upstream source description

SumatraPDF is a multi-format reader for Windows. In 3.6.1 and earlier, FrameOnCommand() handles CmdExec by passing a null current-tab pointer to RunWithExe(), which dereferences WindowTab::filePath. A local process in the same interactive Windows session, at an integrity level greater than or equal to SumatraPDF's under Windows UIPI, can dispatch CmdExec over DDE or WM_COPYDATA while no document tab is open, causing abrupt process termination and loss of unsaved state. No broader impact is claimed beyond the advisory-supported conditions. No fixed version is available as of this review.

Quoted source text, attributed separately from HOL analysis.