Dompdf's usage of vulnerable version of phenx/php-svg-lib leads to restriction bypass and potential RCE

Exploitation

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

CVSS

10.0 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

Summary A lack of sanitization/check in the font path returned by php-svg-lib, in the case of a inline CSS font defined, that will be used by Cpdf to open a font will be passed to a fileexists call, which is sufficient to trigger metadata unserializing on a PHAR file, through the phar:// URL handler on PHP < 8.0. On other versions, it might be used as a way to get a SSRF through, for example, ftp, not restricted by authorized protocols configured on dompdf. Details The problem lies on the openFont function of the lib/Cpdf.php library, when the $font variable passed by php-svg-lib isn't checked correctly. A path is crafted through $name and $dir, which are two values that can be controlled through CSS : Passing a font named phar:///foo/bar/baz.phar/test will set the value of $name to test and $dir to phar:///foo/bar/baz.phar, which once reconstructed will call fileexists on phar:///foo/bar/baz.phar/test.ufm. That allows to deserialize the baz.phar arbitrary file that contains a…

Published by the source

22 Feb 2024, 18:15 UTC

Last modified by the source

24 Mar 2026, 05:03 UTC

Source last checked

26 Oct 2026, 14:38 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-97m3-52wr-xvv2

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# Patch Next advisory brief: GHSA-97m3-52wr-xvv2

Advisory: Dompdf's usage of vulnerable version of phenx/php-svg-lib leads to restriction bypass and potential RCE
IDs: GHSA-97m3-52wr-xvv2
Record: https://patchnext.com/advisories/ghsa-97m3-52wr-xvv2 (revision 1, source checked 26 Oct 2026, 14:38 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Critical (CVSS 10.0)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: phenx/php-svg-lib 0.5.2. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist phenx/php-svg-lib: affected < 0.5.2; fixed in 0.5.2

## Suggested inspection (read-only)
- Packagist phenx/php-svg-lib: 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 phenx/php-svg-lib.
- 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-97m3-52wr-xvv2 (GitHub-reviewed advisory GHSA-97m3-52wr-xvv2 lists affected ranges: Packagist phenx/php-svg-lib >=0 <0.5.2)

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