CVE-2023-50251: php-svg-lib possible DoS caused by infinite recursion when parsing SVG document

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.9% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2023-12-12 · updated 2026-06-17
Weakness: CWE-674

Description

php-svg-lib is an SVG file parsing / rendering library. Prior to version 0.5.1, when parsing the attributes passed to a `use` tag inside an svg document, an attacker can cause the system to go to an infinite recursion. Depending on the system configuration and attack pattern this could exhaust the memory available to the executing process and/or to the server itself. An attacker sending multiple request to a system to render the above payload can potentially cause resource exhaustion to the point that the system is unable to handle incoming request. Version 0.5.1 contains a patch for this issue.

Affected products

dompdf php-svg-lib: before 0.5.1 — fixed in 0.5.1
Packagist Phenx/Php-Svg-Lib: before 0.5.1; 0.1, 0.3.4, 0.4.0, 0.4.1, 0.5.0, v0.2 (+4) — fixed in 0.5.1

How to fix

Upgrade to a fixed version: dompdf php-svg-lib 0.5.1; Packagist Phenx/Php-Svg-Lib 0.5.1. Check the vendor advisory for mitigations.

References

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