UBUNTU-CVE-2026-55555

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Source
https://ubuntu.com/security/CVE-2026-55555
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-55555.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-55555
Upstream
Published
2026-07-30T00:00:00Z
Modified
2026-07-30T16:00:27.066627148Z
Severity
  • 2.3 (Low) CVSS_V4 - 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 CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

Dompdf is an HTML to PDF converter for PHP. Versions 3.15 and prior are vulnerable to a File Existence Oracle attack through the manipulation of the CSS @font-face directive. By providing malicious HTML that references local files via the file:// protocol repeatedly, an attacker can trigger PHP memory exhaustion. Because Dompdf behaves differently depending on whether a referenced local file exists (an existing file is processed repeatedly until it triggers an "Allowed memory size exhausted" crash, whereas a missing file fails fast or is ignored and never hits the memory limit), an attacker can use this observable discrepancy as an oracle to enumerate sensitive files on the server regardless of CHROOT restrictions. Exploitation requires the attacker to supply unrestricted or unsanitized HTML in a request that permits large data, plus a configuration where Dompdf's memory limit is low enough to be exhausted (with  $dompdfshow_warnings=true  making the overflow easier to reach). This issue has been fixed in version 3.16.

References

Affected packages

Ubuntu:Pro:16.04:LTS / php-dompdf

Package

Name
php-dompdf
Purl
pkg:deb/ubuntu/php-dompdf?arch=source&distro=esm-apps%2Fxenial

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

0.*
0.6.1+dfsg-2
0.6.1+dfsg-2build1
0.6.1+dfsg-2ubuntu1
0.6.1+dfsg-2ubuntu1+esm1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "php-dompdf",
            "binary_version": "0.6.1+dfsg-2ubuntu1+esm1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-55555.json"

Ubuntu:Pro:18.04:LTS / php-dompdf

Package

Name
php-dompdf
Purl
pkg:deb/ubuntu/php-dompdf?arch=source&distro=esm-apps%2Fbionic

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

0.*
0.6.2+dfsg-3
0.6.2+dfsg-3ubuntu0.18.04.1~esm1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "php-dompdf",
            "binary_version": "0.6.2+dfsg-3ubuntu0.18.04.1~esm1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-55555.json"

Ubuntu:20.04:LTS / php-dompdf

Package

Name
php-dompdf
Purl
pkg:deb/ubuntu/php-dompdf?arch=source&distro=focal

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

0.*
0.6.2+dfsg-3
0.6.2+dfsg-3ubuntu0.20.04.1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "php-dompdf",
            "binary_version": "0.6.2+dfsg-3ubuntu0.20.04.1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-55555.json"

Ubuntu:22.04:LTS / php-dompdf

Package

Name
php-dompdf
Purl
pkg:deb/ubuntu/php-dompdf?arch=source&distro=jammy

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

0.*
0.6.2+dfsg-3.1
0.6.2+dfsg-3.1ubuntu0.1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "php-dompdf",
            "binary_version": "0.6.2+dfsg-3.1ubuntu0.1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-55555.json"