How severe is GHSA-56gj-mvh6-rp75?

GHSA-56gj-mvh6-rp75 has a CVSS score of 10/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by GHSA-56gj-mvh6-rp75?

GHSA-56gj-mvh6-rp75 affects the following packages: dompdf/dompdf (Packagist). Ecosystems affected: Packagist.

How do I fix GHSA-56gj-mvh6-rp75?

Update dompdf/dompdf to 2.0.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-56gj-mvh6-rp75 is resolved across your whole dependency graph.

How do I detect GHSA-56gj-mvh6-rp75 in my Packagist dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for dompdf/dompdf. 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.

How do I mitigate GHSA-56gj-mvh6-rp75 if there is no patch (or I can't update yet)?

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 does O3 Security protect against GHSA-56gj-mvh6-rp75?

O3 pinpoints whether GHSA-56gj-mvh6-rp75 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is GHSA-56gj-mvh6-rp75 actively exploited in the wild?

Yes. There are 1 known exploit references for GHSA-56gj-mvh6-rp75, including 1 in-the-wild exploitation observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for GHSA-56gj-mvh6-rp75?

GHSA-56gj-mvh6-rp75 has an EPSS (Exploit Prediction Scoring System) score of 2.5%, placing it in the 83th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is GHSA-56gj-mvh6-rp75?

GHSA-56gj-mvh6-rp75 is classified as CWE-436 (CWE-436). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-56gj-mvh6-rp75 published, and has it been updated?

GHSA-56gj-mvh6-rp75 was published on February 7, 2023 and was last updated on November 8, 2023. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐘 Packagist

GHSA-56gj-mvh6-rp75

CRITICAL

URI validation failure on SVG parsing. Bypass of CVE-2023-23924

Also known asCVE-2023-24813

Published

Feb 7, 2023

Updated

Nov 8, 2023

Affected

1 pkg

Patched

1 / 1

Exploits

1 known

EPSS Exploitation Probability

via FIRST.org ↗

2.5%probability of exploitation in next 30 days

Lower Risk83th percentile-6.83%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

1 pkg affected

🐘dompdf/dompdf

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.

Description

Summary

Due to the difference in the attribute parser of Dompdf and php-svg-lib, an attacker can still call arbitrary URLs with arbitrary protocols.

Details

Dompdf parses the href attribute of image tags with the following code:

src/Image/Cache.php line 135-150

function ($parser, $name, $attributes) use ($options, $parsed_url, $full_url) {
    if (strtolower($name) === "image") {
        $attributes = array_change_key_case($attributes, CASE_LOWER);
        $url = $attributes["xlink:href"] ?? $attributes["href"];
        if (!empty($url)) {
            $inner_full_url = Helpers::build_url($parsed_url["protocol"], $parsed_url["host"], $parsed_url["path"], $url);
            if ($inner_full_url === $full_url) {
                throw new ImageException("SVG self-reference is not allowed", E_WARNING);
            }
            [$resolved_url, $type, $message] = self::resolve_url($url, $parsed_url["protocol"], $parsed_url["host"], $parsed_url["path"], $options);
            if (!empty($message)) {
                throw new ImageException("This SVG document references a restricted resource. $message", E_WARNING);
            }
        }
    }
},

As you can see from the code snippet above, it respects xlink:href even if href is specified.

$url = $attributes["xlink:href"] ?? $attributes["href"];

However, php-svg-lib, which is later used to parse the svg file, parses the href attribute with the following code:

src/Svg/Tag/Image.php line 51-57

if (isset($attributes['xlink:href'])) {
    $this->href = $attributes['xlink:href'];
}

if (isset($attributes['href'])) {
    $this->href = $attributes['href'];
}

Since href is respected if both xlink:href and href is specified, it's possible to bypass the protection on the Dompdf side by providing an empty xlink:href attribute.

Impact

An attacker can exploit the vulnerability to call arbitrary URLs with arbitrary protocols if they provide an SVG file to the Dompdf. In PHP versions before 8.0.0, it leads to arbitrary unserialize, which will lead, at the very least, to arbitrary file deletion and might lead to remote code execution, depending on available classes.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`dompdf/dompdf`	≥ 2.0.2&&< 2.0.3	2.0.3

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

Dompdf is an HTML to PDF converter written in php. Due to the difference…

github.comNVDFeb 2023

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for dompdf/dompdf. 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.
Fix
Update dompdf/dompdf to 2.0.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-56gj-mvh6-rp75 is resolved across your whole dependency graph.
Workarounds
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 GHSA-56gj-mvh6-rp75 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 GHSA-56gj-mvh6-rp75. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### Summary Due to the difference in the attribute parser of Dompdf and php-svg-lib, an attacker can still call arbitrary URLs with arbitrary protocols. ### Details Dompdf parses the href attribute of `image` tags with the following code: [`src/Image/Cache.php` line 135-150](https://github.com/dompdf/dompdf/blob/2a8a6b80fcaa5148ace50f35a10979fe00c6a35d/src/Image/Cache.php#L135-L150) ``` php function ($parser, $name, $attributes) use ($options, $parsed_url, $full_url) { if (strtolower($name) === "image") { $attributes = array_change_key_case($attributes, CASE_LOWER); $url

O3 Security · Impact-Aware SCA

Is GHSA-56gj-mvh6-rp75 in your dependencies?

O3 detects GHSA-56gj-mvh6-rp75 across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works