Dompdf vulnerable to URI validation failure on SVG parsing

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:L/A:H

EPSS

• CVE-2023-23924: 3.57% estimated exploitation activity in the next 30 days; percentile 89.38 (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.

Summary The URI validation on dompdf 2.0.1 can be bypassed on SVG parsing by passing <image tags with uppercase letters. This might leads to arbitrary object unserialize on PHP < 8, through the phar URL wrapper. Details The bug occurs during SVG parsing of <image tags, in src/Image/Cache.php : This part will try to detect <image tags in SVG, and will take the href to validate it against the protocolAllowed whitelist. However, the $name comparison with "image" is case sensitive, which means that such a tag in the SVG will pass : As the tag is named "Image" and not "image", it will not pass the condition to trigger the check. A correct solution would be to strtolower the $name before the check : PoC Parsing the following SVG file is sufficient to reproduce the vulnerability : Impact An attacker might be able to exploit the vulnerability to call arbitrary URL with arbitrary protocols, if they can provide a SVG file to dompdf. In PHP versions before 8.0.0, it leads to arbitrary…

Published by the source

1 Feb 2023, 01:37 UTC

Last modified by the source

15 Mar 2023, 19:18 UTC

Source last checked

26 Oct 2026, 14:05 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-3cw5-7cxw-v5qg

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# Patch Next advisory brief: CVE-2023-23924

Advisory: Dompdf vulnerable to URI validation failure on SVG parsing
IDs: CVE-2023-23924, GHSA-3cw5-7cxw-v5qg
Record: https://patchnext.com/advisories/cve-2023-23924 (revision 1, source checked 26 Oct 2026, 14:05 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: dompdf/dompdf 2.0.2. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist dompdf/dompdf: affected < 2.0.2; fixed in 2.0.2

## 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-3cw5-7cxw-v5qg (GitHub-reviewed advisory GHSA-3cw5-7cxw-v5qg lists affected ranges: Packagist dompdf/dompdf >=0 <2.0.2)

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