Dompdf: Local file read due to improper file path validation in SVG images encoded as data-URI

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

6.3 · CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N · score source

EPSS

• CVE-2026-56722: 0.45% estimated exploitation activity in the next 30 days; percentile 38.99 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Description: An attacker, who controls the HTML input supplied to dompdf, can read arbitrary images from the server’s file system, bypassing the chroot restriction. The vulnerability is exploitable in the default configuration. Exploitation conditions: An external user Researcher: Nikita Sveshnikov (Positive Technologies) Research dompdf restricts access to local files using the chroot mechanism. By default, chroot is set to the root directory of dompdf (Options.php:350-351): Listing 1. chroot settings When the HTML references a local file, Options::validateLocalUri() checks that the path resides within сhroot. A direct link to the file outside this directory is correctly blocked: Listing 2. Blocking link How the protection is bypassed: An attacker wraps the link to the target file in SVG format and delivers it via data: URI: Listing 3. Wrapping link in SVG Inside the base64 payload is an SVG containing the <image element that points to the target file: Listing 4. Pointing to the…

Published by the source

22 Jul 2026, 21:30 UTC

Last modified by the source

22 Jul 2026, 21:30 UTC

Source last checked

26 Oct 2026, 14:50 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-cx96-42px-69fm

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# Patch Next advisory brief: CVE-2026-56722

Advisory: Dompdf: Local file read due to improper file path validation in SVG images encoded as data-URI
IDs: CVE-2026-56722, GHSA-cx96-42px-69fm
Record: https://patchnext.com/advisories/cve-2026-56722 (revision 1, source checked 26 Oct 2026, 14:50 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: dompdf/dompdf 3.1.6. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist dompdf/dompdf: affected < 3.1.6; fixed in 3.1.6

## Suggested inspection (read-only)
- Packagist dompdf/dompdf: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on dompdf/dompdf.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-cx96-42px-69fm (GitHub-reviewed advisory GHSA-cx96-42px-69fm lists affected ranges: Packagist dompdf/dompdf >=0 <3.1.6)

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