CVE-2026-46643
CVE-2026-46643 is a OS Command Injection vulnerability in KnpLabs/knp-snappy. O3 Security confirms whether CVE-2026-46643 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Snappy: Binary path is never shell-escaped due to an inverted is_executable check
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-46643.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Real-World Exposure
KnpLabs/knp-snappyReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
Snappy is a PHP library allowing thumbnail, snapshot or PDF generation from a url or a html page. Prior to version 1.7.1, on POSIX, escapeshellarg(‘/usr/bin/wkhtmltopdf’) returns the literal string ‘/usr/bin/wkhtmltopdf’ with the single-quote characters included. is_executable() then looks for a file whose actual name contains those quote characters, which essentially never exists. The safe branch is dead code and $command always falls through to the raw, unescaped value. The rest of the arguments (options, input, output) are escaped correctly, so injection has to land in the binary string itself. That happens whenever the binary path is sourced from configuration that is user-influenced, derived from environment variables that ultimately come from request data, or concatenated with any user-controlled fragment. This issue has been patched in version 1.7.1.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | KnpLabs/knp-snappy | all versions | 1.7.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for KnpLabs/knp-snappy. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update KnpLabs/knp-snappy to 1.7.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-46643 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-46643 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-46643. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-46643 in your dependencies?
O3 detects CVE-2026-46643 across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.