CVE-2026-107734

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.

CVSS 4.0

7.1CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

EPSS

0.2% chance of exploitation in the next 30 days; higher than 9% of CVEs (scores of 2026-10-25)

CWEs

CWE-20, CWE-88

Published

2026-10-08

Modified

2026-10-09

Record from

the NVD, synced 2026-10-19

References

• https://github.com/sumatrapdfreader/sumatrapdf/commit/398d23624362c60722d9709173a287ea53545b3b
• https://github.com/sumatrapdfreader/sumatrapdf/security/advisories/GHSA-jf4v-rw66-j4w2
• https://github.com/sumatrapdfreader/sumatrapdf/security/advisories/GHSA-jf4v-rw66-j4w2

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