CVE-2023-50251Public exploitNetwork attack vector

Process crash via self-referential SVG use element

Published Dec 12, 2023 · Updated May 22, 2025

Uncontrolled recursion in dompdf php-svg-lib before 0.5.1 allows remote attackers to crash SVG-rendering processes via crafted SVG input. Svg\Tag\UseTag::before resolves href or xlink:href to a definition and recursively invokes before() without detecting a self-reference. Unauthenticated reachability requires a consuming application to accept attacker-controlled SVG for rendering; a self-referencing use element exhausts PHP memory and crashes the rendering process.

CVSS severity5.3
Medium
EPSS probability0.88%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Uncontrolled recursion in dompdf php-svg-lib before 0.5.1 allows remote attackers to crash SVG-rendering processes via crafted SVG input. Svg\Tag\UseTag::before resolves href or xlink:href to a definition and recursively invokes before() without detecting a self-reference. Unauthenticated reachability requires a consuming application to accept attacker-controlled SVG for rendering; a self-referencing use element exhausts PHP memory and crashes the rendering process.

The record

CVE
CVE-2023-50251
Published
Dec 12, 2023
Updated
May 22, 2025
Vendor
dompdf
Product
php-svg-lib
Classifications
CWE-674, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 12, 2023CVE publishedPublication date reported by the CVE source.
  2. May 22, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 0.5.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

dompdf · php-svg-libversion=< 0.5.1

Published CVSS scores

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
5.3GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-674Uncontrolled Recursion
T1499Endpoint Denial of Service

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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