cve-2026-59942

MEDIUM CVSS 6.3 cvelistv5
Description

Dompdf is an HTML to PDF converter for PHP. Versions 3.15 and prior are vulnerable to a Denial of Service (DoS) attack via resource exhaustion. An attacker can crash the PHP process by providing a specially crafted HTML document containing a single image with massive dimensions (e.g., 30,000x30,000 pixels). While Dompdf implements internal checks to validate image dimensions, these can be bypassed by using a high-entropy image (such as random noise) encoded in Base64 and wrapped in specific CSS containers. The vulnerability exists because the dimension validation happens early, but the resource allocation for calculating the object's bounding box and internal buffers during the rendering phase does not strictly limit the cumulative CPU time or memory usage for a single object that has passed the initial check. An unauthenticated remote attacker can cause a complete Denial of Service on the web server by submitting a crafted HTML string. This affects any application that allows users to provide HTML content or URLs that are subsequently converted to PDF using Dompdf. This issue has been fixed in version 3.16.

Timeline
Published
2026-07-28 20:41 UTC
Last Modified
2026-07-29
CVSS Details
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
Affected Products
  • dompdf dompdf
Weaknesses (CWE)
CWE-400
SSVC (CISA Stakeholder-Specific Vulnerability Categorization) CISA Coordinator v2.0.3
Exploitation
poc
Automatable
yes
Technical Impact
partial
Decision timestamp
2026-07-29T14:07:38.614960Z

What is SSVC? — CISA's vulnerability-prioritisation framework using a decision tree rather than a single score.

References
Linked Vulnerabilities

No linked vulnerabilities found.

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