CVE-2026-16770
CVE-2026-16770 is a CWE-88 vulnerability. O3 Security confirms whether CVE-2026-16770 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
PDF::WebKit versions through 1.2 for Perl allow argument injection into wkhtmltopdf via meta tags in the source document. For an HTML string or file source, the constructor collects…
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-16770.
Description
PDF::WebKit versions through 1.2 for Perl allow argument injection into wkhtmltopdf via meta tags in the source document.
For an HTML string or file source, the constructor collects every <meta name="pdf-webkit-KEY" content="VALUE"> element in the document head through _pdf_webkit_meta_tags and turns each one into a wkhtmltopdf command line option. KEY is normalized to an option name matching --[a-z0-9-]+ but is not checked against an allow list, VALUE is passed through unchanged as the argument that follows it, and a VALUE of "yes" emits the option as a bare flag. BUILD merges the meta derived options last, so they also override the module defaults and the options passed to new. Switches such as --enable-local-file-access and --cookie-jar are reachable this way. The renderer is executed with an argument list rather than a shell command, so this is argument injection and not shell injection.
Any caller that renders untrusted HTML lets the document choose the renderer's options and override those set by the application, including options that read local files into the resulting PDF or write to a chosen path. A URL source is not scanned, and the scan is skipped when XML::LibXML, a recommended dependency, is not installed.
Detection & mitigation playbook
VulnerabilityDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for the affected component. 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.
Remediation status
No patched version of the affected component has shipped for CVE-2026-16770 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
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-2026-16770 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-2026-16770. 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-2026-16770 in your dependencies?
O3 detects CVE-2026-16770 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.