CVE-2026-55554

What it is

Dompdf is an HTML to PDF converter for PHP. In versions 3.15 and prior, the validateLocalUri() method enforces chroot boundaries with a strpos() prefix check after normalizing paths with  realpath() . Because normalization strips the trailing directory separator from  $chrootPath , the check only verifies that  $chrootPath  is a string prefix of $realfile, so a chroot of  /var/www  also matches sibling directories like /var/www2 , /var/www-admin, or /var/www_backup. An attacker who controls part of the rendered HTML could exploit this to escape the chroot and read sensitive files outside the allowed directory. This issue has been fixed in version 3.16.

At a glance

Exploitability

Can be exploited over the network without logging in, but needs a user to act. Limited direct impact.

Exploit odds

0.5% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-07-28 20:17 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-08-05 16:37 UTC Last updatedMost recent change to the record

Details

Published

2026-07-28 20:17 UTC

Last modified

2026-08-05 16:37 UTC

Exploit probability

0.5% · EPSS, next 30 days

Weakness

CWE-20 · Improper input validation

Record status

Analyzed

Affected

• Dompdf Project Dompdf < 3.1.6

Attack profile CVSS 4.0 · 2.3

Attack vector

Network

Complexity

Low

Attack requirements

Present

Privileges needed

None

User interaction

Passive

Confidentiality

Low

Integrity

None

Availability

None