CVE-2026-59942— Dompdf: Denial of Service (DoS) via Resource Exhaustion using Oversized Image Bitmaps

Dompdf: Denial of Service (DoS) via Resource Exhaustion using Oversized Image Bitmaps

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.

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

未加控制的资源消耗(资源穷尽)

dompdf 资源管理错误漏洞

dompdf是dompdf团队开源的一个 HTML 到 PDF 的转换器。 dompdf 3.16之前版本存在资源管理错误漏洞，该漏洞源于资源分配不当，导致远程未认证攻击者通过提交特制的HTML文档（包含超大尺寸图像）造成拒绝服务。

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