---
title: "CVE-2026-55554\n    | Ubuntu"
description: Ubuntu is an open source software operating system that runs from the
  desktop, to the cloud, to all your internet connected things.
url: https://ubuntu.com/security/CVE-2026-55554?format=md
keywords: index, follow
---

# CVE-2026-55554

Publication date 28 July 2026

Last updated 7 August 2026

---

Ubuntu priority

**Medium**

[Why this priority?](https://ubuntu.com/security/cves/about#priority )

## Cvss 3 Severity Score

**7.5 · High**

[Score breakdown](https://ubuntu.com/security/CVE-2026-55554?format=md#impact-score)

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## Description

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.

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| php-dompdf | 26.04 LTS resolute | Not in release |
| 24.04 LTS noble | Not in release |
| 22.04 LTS jammy | Needs evaluation |
| 20.04 LTS focal | Needs evaluation |
| 18.04 LTS bionic | Needs evaluation |
| 16.04 LTS xenial | Needs evaluation |

---

* [How can I get the fixes?](https://ubuntu.com/security/cves/about#security)
* [What do statuses mean?](https://ubuntu.com/security/cves/about#statuses)

## Severity score breakdown

CVSS version:

CVSS v4.0

[CVSS v4.0](https://ubuntu.com/security/CVE-2026-55554?format=md)
[CVSS v3.0](https://ubuntu.com/security/CVE-2026-55554?format=md)

**Base score**

2.3 · Low

* Base metrics

  | Parameter | Value |
  | --- | --- |
  | Attack vector | Network |
  | Attack complexity | Low |
  | Attack requirements | Present |
  | Privileges required | None |
  | User interaction | Passive |
  | Vulnerable system - Confidentiality impact | Low |
  | Vulnerable system - Integrity impact | None |
  | Vulnerable system - Availability impact | None |
  | Subsequent system - Confidentiality impact | None |
  | Subsequent system - Integrity impact | None |
  | Subsequent system - Availability impact | None |
* Scores

  | Parameter | Value |
  | --- | --- |
  | Base score | 2.3 · Low |
  | Base + Threat score | - |
  | Base + Environmental score | - |
  | Base + Threat + Environmental score | - |

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

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2026-55554)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2026-55554)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2026-55554)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2026-55554)

### Other references

* <https://www.cve.org/CVERecord?id=CVE-2026-55554>
* <https://github.com/dompdf/dompdf/security/advisories/GHSA-wvh6-f5jh-8gw4>
* <https://github.com/dompdf/dompdf/releases/tag/v3.1.6>