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 $_dompdf_show_warnings=true making the overflow easier to reach). This issue has been fixed in version 3.16.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - 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     $_dompdf_show_warnings=true making the overflow easier to reach). This issue has been fixed in version     3.16. (CVE-2026-55555)

Note that Nessus relies on the presence of the package as reported by the vendor.

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - 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
    $_dompdf_show_warnings=true making the overflow easier to reach). This issue has been fixed in version
    3.16. (CVE-2026-55555)

ID	Name	Product	Family	Type	Severity
330653	Linux Distros Unpatched Vulnerability : CVE-2026-55555	Nessus	Misc.	Local	low
445195	SCA: security update for dompdf/dompdf (GHSA-7x2p-4jvh-6384)	Tenable Cloud Security	SCA Checks	Local	low
445195	SCA: security update for dompdf/dompdf (GHSA-7x2p-4jvh-6384)	Tenable Self-Hosted Container Security	SCA Checks	Local	low

Detections

Analytics

CVE-2026-55555

low

Tenable Plugins

low

low

low