Vulnerability-Lookup

UBUNTU-CVE-2026-55554 (CVE-2026-55554)

Vulnerability from osv_ubuntu – Published: 2026-07-28 20:17 – Updated: 2026-08-06 19:59 – Source website

Details

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.

Severity

2.3 (Low)


                    
                      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

7.5 (High)


                    
                      CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

N/A (UNKNOWN)


                    
                      medium

References

URL

Type

	https://ubuntu.com/security/CVE-2026-55554	REPORT
	https://www.cve.org/CVERecord?id=CVE-2026-55554	REPORT
	https://github.com/dompdf/dompdf/security/advisor…	REPORT
	https://github.com/dompdf/dompdf/releases/tag/v3.1.6	REPORT

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "php-dompdf",
            "binary_version": "0.6.1+dfsg-2ubuntu1+esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:16.04:LTS",
        "name": "php-dompdf",
        "purl": "pkg:deb/ubuntu/php-dompdf@0.6.1+dfsg-2ubuntu1+esm1?arch=source\u0026distro=esm-apps/xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "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": "0.6.2+dfsg-3ubuntu0.18.04.1~esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:18.04:LTS",
        "name": "php-dompdf",
        "purl": "pkg:deb/ubuntu/php-dompdf@0.6.2+dfsg-3ubuntu0.18.04.1~esm1?arch=source\u0026distro=esm-apps/bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "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-3ubuntu0.20.04.1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:20.04:LTS",
        "name": "php-dompdf",
        "purl": "pkg:deb/ubuntu/php-dompdf@0.6.2+dfsg-3ubuntu0.20.04.1?arch=source\u0026distro=focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "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-3.1ubuntu0.1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "php-dompdf",
        "purl": "pkg:deb/ubuntu/php-dompdf@0.6.2+dfsg-3.1ubuntu0.1?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.6.2+dfsg-3.1",
        "0.6.2+dfsg-3.1ubuntu0.1"
      ]
    }
  ],
  "aliases": [],
  "details": "Dompdf is an HTML to PDF converter for PHP. In versions 3.15 and prior, the\u00a0validateLocalUri()\u00a0method enforces chroot boundaries with a\u00a0strpos() prefix check after normalizing paths with \u00a0realpath()\u00a0. Because normalization strips the trailing directory separator from \u00a0$chrootPath\u00a0, the check only verifies that \u00a0$chrootPath\u00a0 is a string prefix of\u00a0$realfile, so a chroot of \u00a0/var/www\u00a0 also matches sibling directories like /var/www2\u00a0, /var/www-admin, or\u00a0/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.",
  "id": "UBUNTU-CVE-2026-55554",
  "modified": "2026-08-06T19:59:15Z",
  "published": "2026-07-28T20:17:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-55554"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-55554"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/dompdf/dompdf/security/advisories/GHSA-wvh6-f5jh-8gw4"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/dompdf/dompdf/releases/tag/v3.1.6"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "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",
      "type": "CVSS_V4"
    },
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-55554"
  ]
}

CVE-2026-55554 (GCVE-0-2026-55554)

Vulnerability from cvelistv5 – Published: 2026-07-28 19:28 – Updated: 2026-07-29 15:24

Title

Dompdf: Chroot Validation Bypass

Summary

Severity

2.3 (Low)


                        
                          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

SSVC

Exploitation: poc Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-07-29 13:23 UTC

CWE

CWE-20 - Improper Input Validation

Assigner

GitHub_M mitre root

References

2 references

URL	Tags
https://github.com/dompdf/dompdf/security/advisor…	x_refsource_CONFIRM
https://github.com/dompdf/dompdf/releases/tag/v3.1.6	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
dompdf	dompdf	Affected: < 3.1.6

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-55554",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-07-29T13:23:30.682270Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-07-29T15:24:54.517Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "exploit"
            ],
            "url": "https://github.com/dompdf/dompdf/security/advisories/GHSA-wvh6-f5jh-8gw4"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "dompdf",
          "vendor": "dompdf",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 3.1.6"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Dompdf is an HTML to PDF converter for PHP. In versions 3.15 and prior, the\u00a0validateLocalUri()\u00a0method enforces chroot boundaries with a\u00a0strpos() prefix check after normalizing paths with \u00a0realpath()\u00a0. Because normalization strips the trailing directory separator from \u00a0$chrootPath\u00a0, the check only verifies that \u00a0$chrootPath\u00a0 is a string prefix of\u00a0$realfile, so a chroot of \u00a0/var/www\u00a0 also matches sibling directories like /var/www2\u00a0, /var/www-admin, or\u00a0/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."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "attackVector": "NETWORK",
            "baseScore": 2.3,
            "baseSeverity": "LOW",
            "privilegesRequired": "NONE",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "PASSIVE",
            "vectorString": "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",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "LOW",
            "vulnIntegrityImpact": "NONE"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-20",
              "description": "CWE-20: Improper Input Validation",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-28T19:28:43.838Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/dompdf/dompdf/security/advisories/GHSA-wvh6-f5jh-8gw4",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/dompdf/dompdf/security/advisories/GHSA-wvh6-f5jh-8gw4"
        },
        {
          "name": "https://github.com/dompdf/dompdf/releases/tag/v3.1.6",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/dompdf/dompdf/releases/tag/v3.1.6"
        }
      ],
      "source": {
        "advisory": "GHSA-wvh6-f5jh-8gw4",
        "discovery": "UNKNOWN"
      },
      "title": "Dompdf: Chroot Validation Bypass"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-55554",
    "datePublished": "2026-07-28T19:28:43.838Z",
    "dateReserved": "2026-06-16T23:11:20.213Z",
    "dateUpdated": "2026-07-29T15:24:54.517Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.