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.
CVE-2026-107734
HIGHPre-NVD 7.17.1Trending — 3 sources updated this weekElevated
EchelonGraph scoreLOW confidence
This high-severity CVE scores 7.1 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
Triggered by: NVD CVSS baseline
Sources: secondary
7.1EG
EchelonGraph verdictPlan mitigationSerious severity, but no confirmed exploitation yet.
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.1%CVSS: 7.1Exploit: Elevated riskExposed services: Not assessed
No fix is confirmed yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for the fix.
- CVSS v3
- 7.1
- EG Score
- 7.1HIGHlow confidence
- EG Risk
- 48EG Risk 48/100CISA SSVC
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity71% × 45%Exploitation40% × 40%Automatability0% × 15%CISA SSVC: Track at low, Track* at medium and Attend at high mission impact.Action: No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high, and watch the vendor's advisory for the fix. - EPSS PROB
- 0.1%
- EPSS %ILE
- 2nd
- KEV
- Not listed
CISA SSVCTrack at low, Track* at medium and Attend at high mission impact.
No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high, and watch the vendor's advisory for the fix.
Exploitation public PoC (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table
Published
October 8, 2026
Last Modified
October 9, 2026
Advisory Details (2)
Auto-updated Oct 8, 2026🔬 Proof of concept available. No fix on record yet. Sources: github, github_commit.
github_commit
commit 398d23624362 (sumatrapdfreader/sumatrapdf)
Fix landed in sumatrapdfreader/sumatrapdf commit 398d23624362 — awaiting tagged release
https://github.com/sumatrapdfreader/sumatrapdf/commit/398d23624362c60722d9709173a287ea53545b3bgithubMentions a patch (unverified)🟡 PoC Available
SyncTeX Argument Injection in Inverse Search Enables Arbitrary Command Execution via External Editors · Advisory · sumatrapdfreader/sumatrapdf · GitHub
https://github.com/sumatrapdfreader/sumatrapdf/security/advisories/GHSA-jf4v-rw66-j4w2Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 6× in last 7d / 6× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-10-09 20:06 UTCEPSS rescore
- 2026-10-09 16:34 UTCEG score recompute
- 2026-10-09 15:48 UTCEG score recompute
- 2026-10-08 23:22 UTCEG score recompute
- 2026-10-08 22:28 UTCEG score recompute
- 2026-10-08 22:28 UTCMITRE cvelistV5first tracked
Related CVEs(same CWE)
Frequently asked(5)
What is CVE-2026-107734?
CVE-2026-107734 is a high vulnerability published on October 8, 2026. 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…
When was CVE-2026-107734 disclosed?
CVE-2026-107734 was first published on October 8, 2026, with the most recent update on October 9, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-107734 actively exploited?
CVE-2026-107734 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.1% probability of exploitation in the next 30 days (2nd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-107734?
CVE-2026-107734 has a CVSS base score of 7.1 (a secondary CVSS source that NVD displays; NVD's own analysis pending). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-107734?
No fix for CVE-2026-107734 is confirmed yet. Until one is published, restrict network exposure of the affected system or apply the vendor's mitigation — for example, keep it off the internet or limit it to trusted networks — and watch the vendor's advisory for the fix.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-107734
Is Your Infrastructure Affected by CVE-2026-107734?
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