CVE-2026-56722: Input Validation Flaw

Description

Dompdf is an HTML to PDF converter for PHP. In versions 3.15 and prior, aAn attacker who controls the HTML input can bypass this restriction by embedding a target file path inside an SVG image delivered through a data: URI, because dompdf processes the SVG twice and the second pass does not enforce the same protections as the first. When rendering, dompdf hands the SVG to the separate php-svg-lib library with external references forced on, and that library has no knowledge of the chroot directory, blocks only the phar:// scheme, and ultimately reads the referenced file with no path or protocol validation. This lets an external, unauthenticated attacker read arbitrary image files from the server's file system in the default configuration. This issue has been fixed in version 3.16.

Is your site exposed to CVE-2026-56722?

Run a free security scan — no signup, results in seconds.

EPSS — Exploit Prediction

0.0045

Probability of exploitation

0.37%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-20 Improper Input Validation

References

Other References

https://github.com/dompdf/dompdf/commit/6a58996865db05d8fede748507e50ac4b8c5bfd0 https://github.com/dompdf/dompdf/commit/bf7b02f642e26007dedc5a22b3d6e15f9931120a https://github.com/dompdf/dompdf/releases/tag/v3.1.6 https://github.com/dompdf/dompdf/security/advisories/GHSA-cx96-42px-69fm https://github.com/dompdf/dompdf/security/advisories/GHSA-cx96-42px-69fm

Frequently Asked Questions

What is CVE-2026-56722? +

Dompdf is an HTML to PDF converter for PHP. In versions 3.15 and prior, aAn attacker who controls the HTML input can bypass this restriction by embedding a target file path inside an SVG image delivered through a data: URI, because dompdf processes the SVG twice and the second pass does not enforce the same protections as the first. When rendering, dompdf hands the SVG to the separate php-svg-lib library with external references forced on, and that library has no knowledge of the chroot directory, blocks only the phar:// scheme, and ultimately reads the referenced file with no path or protocol validation. This lets an external, unauthenticated attacker read arbitrary image files from the server's file system in the default configuration. This issue has been fixed in version 3.16.

How do I check if I'm vulnerable to CVE-2026-56722? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2025-13826

Zervit's portable HTTP/web server is vulnerable to remote DoS attacks when a configuration reset request is made. The vulnerability is …

CVE-2026-62658

A security flaw was discovered in certain NETGEAR Nighthawk RAX series routers that could allow someone already logged in to …

CVE-2024-54011

Penetration Testing engineers at Amazon have discovered a flaw where the camera system fails to properly handle data supplied in …

CVE-2026-56349

n8n before version 2.10.0 contains an input validation vulnerability in the Guardrail node that allows attackers to bypass default guardrail …

CVE-2026-6409

A Denial of Service (DoS) vulnerability exists in the Protobuf PHP library during the parsing of untrusted input. Maliciously structured …

CVE-2026-59650

In Bouncy Castle for Java before 1.85, MTI/A0 DH agreement exponentiates unvalidated peer value. This issue also affects Bouncy Castle …

CVE-2026-56722