CVE-2026-107734 SumatraPDF: SyncTeX Argument Injection in Inverse Search Enables Arbitrary Command Execution via External Editors
Attackers can execute arbitrary commands via crafted SyncTeX files in SumatraPDF if an external editor is configured and inverse search is used.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-107734?
CVE-2026-107734 is a high-severity command injection vulnerability in sumatrapdfreader sumatrapdf, published on 8 Oct 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
SumatraPDF is a multi-format reader for Windows. In 3.5.2 and earlier, an attacker-controlled SyncTeX source filename is substituted 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; the resulting impact depends on the target editor interpreting those flags and can include unintended editor actions or code execution through a malicious extension. No broader impact is claimed beyond the advisory-supported conditions. No fixed version is available as of this review.
Which versions are affected by CVE-2026-107734?
How do I fix CVE-2026-107734?
No fix has been published for CVE-2026-107734 yet. Limit exposure of the affected software until one is available.
Upgrade, and pass arguments to programs as a list instead of through a shell. More about Command injection.
Is CVE-2026-107734 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-107734 exists.
Sources
Also known as GHSA-jf4v-rw66-j4w2.