GCVE Workshop - 22 September 2026 (14:00-18:00), Luxembourg Before The Vulnopticon Conference - Registration

CVE-2026-42590 (GCVE-0-2026-42590)

Vulnerability from cvelistv5 – Published: 2026-05-14 15:36 – Updated: 2026-05-15 15:57
VLAI
Title
Gotenberg: ExifTool group-prefix syntax bypasses dangerous-tag blocklist
Summary
Gotenberg is a Docker-powered stateless API for PDF files. Prior to 8.30.0, The ExifTool metadata write blocklist in Gotenberg can be bypassed using ExifTool's group-prefix syntax, enabling arbitrary file rename, move, hardlink, and symlink creation on the server. ExifTool supports group-prefix syntax where File:FileName is processed identically to FileName -- the prefix is stripped by SetNewValue in Writer.pl before tag matching. The safeKeyPattern regex (^[a-zA-Z0-9\-_.:]+$) allows colons, so prefixed tag names pass validation. Any prefix works: File:FileName, System:Directory, a:HardLink, etc. Additionally, FilePermissions, FileUserID, and FileGroupID pseudo-tags are not blocked at all and can modify file attributes without any prefix. This vulnerability is fixed in 8.30.0.
Severity
8.2 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L
SSVC
Exploitation: poc Automatable: yes Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-05-15 15:57 UTC
CWE
  • CWE-184 - Incomplete List of Disallowed Inputs
Assigner
References
Impacted products
Vendor Product Version CPE status
gotenberg gotenberg Affected: < 8.30.0
guessed Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-42590",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-05-15T15:57:03.096551Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-05-15T15:57:55.433Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "exploit"
            ],
            "url": "https://github.com/gotenberg/gotenberg/security/advisories/GHSA-7v3r-m9c8-r855"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "gotenberg",
          "vendor": "gotenberg",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 8.30.0"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Gotenberg is a Docker-powered stateless API for PDF files. Prior to 8.30.0, The ExifTool metadata write blocklist in Gotenberg can be bypassed using ExifTool\u0027s group-prefix syntax, enabling arbitrary file rename, move, hardlink, and symlink creation on the server. ExifTool supports group-prefix syntax where File:FileName is processed identically to FileName -- the prefix is stripped by SetNewValue in Writer.pl before tag matching. The safeKeyPattern regex (^[a-zA-Z0-9\\-_.:]+$) allows colons, so prefixed tag names pass validation. Any prefix works: File:FileName, System:Directory, a:HardLink, etc. Additionally, FilePermissions, FileUserID, and FileGroupID pseudo-tags are not blocked at all and can modify file attributes without any prefix. This vulnerability is fixed in 8.30.0."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "LOW",
            "baseScore": 8.2,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "NONE",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-184",
              "description": "CWE-184: Incomplete List of Disallowed Inputs",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-14T15:36:30.386Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/gotenberg/gotenberg/security/advisories/GHSA-7v3r-m9c8-r855",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/gotenberg/gotenberg/security/advisories/GHSA-7v3r-m9c8-r855"
        }
      ],
      "source": {
        "advisory": "GHSA-7v3r-m9c8-r855",
        "discovery": "UNKNOWN"
      },
      "title": "Gotenberg: ExifTool group-prefix syntax bypasses dangerous-tag blocklist"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-42590",
    "datePublished": "2026-05-14T15:36:30.386Z",
    "dateReserved": "2026-04-29T00:31:15.724Z",
    "dateUpdated": "2026-05-15T15:57:55.433Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-42590",
      "date": "2026-09-17",
      "epss": "0.0029",
      "percentile": "0.21682"
    },
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "product": "gotenberg",
                "vendor": "gotenberg",
                "versions": [
                  {
                    "status": "affected",
                    "version": "\u003c 8.30.0"
                  }
                ]
              }
            ],
            "source": "security-advisories@github.com"
          }
        ],
        "configurations": [
          {
            "nodes": [
              {
                "cpeMatch": [
                  {
                    "criteria": "cpe:2.3:a:thecodingmachine:gotenberg:*:*:*:*:*:*:*:*",
                    "matchCriteriaId": "98BC90F8-D193-4721-9254-A0A5670EBC26",
                    "versionEndExcluding": "8.30.0",
                    "vulnerable": true
                  }
                ],
                "negate": false,
                "operator": "OR"
              }
            ]
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "Gotenberg is a Docker-powered stateless API for PDF files. Prior to 8.30.0, The ExifTool metadata write blocklist in Gotenberg can be bypassed using ExifTool\u0027s group-prefix syntax, enabling arbitrary file rename, move, hardlink, and symlink creation on the server. ExifTool supports group-prefix syntax where File:FileName is processed identically to FileName -- the prefix is stripped by SetNewValue in Writer.pl before tag matching. The safeKeyPattern regex (^[a-zA-Z0-9\\-_.:]+$) allows colons, so prefixed tag names pass validation. Any prefix works: File:FileName, System:Directory, a:HardLink, etc. Additionally, FilePermissions, FileUserID, and FileGroupID pseudo-tags are not blocked at all and can modify file attributes without any prefix. This vulnerability is fixed in 8.30.0."
          }
        ],
        "id": "CVE-2026-42590",
        "lastModified": "2026-06-17T10:48:06.670",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "NETWORK",
                "availabilityImpact": "LOW",
                "baseScore": 8.2,
                "baseSeverity": "HIGH",
                "confidentialityImpact": "NONE",
                "integrityImpact": "HIGH",
                "privilegesRequired": "NONE",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L",
                "version": "3.1"
              },
              "exploitabilityScore": 3.9,
              "impactScore": 4.2,
              "source": "security-advisories@github.com",
              "type": "Secondary"
            }
          ],
          "ssvcV203": [
            {
              "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "ssvcData": {
                "id": "CVE-2026-42590",
                "options": [
                  {
                    "exploitation": "poc"
                  },
                  {
                    "automatable": "yes"
                  },
                  {
                    "technicalImpact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-05-15T15:57:03.096551Z",
                "version": "2.0.3"
              }
            }
          ]
        },
        "published": "2026-05-14T16:16:22.010",
        "references": [
          {
            "source": "security-advisories@github.com",
            "tags": [
              "Exploit",
              "Vendor Advisory"
            ],
            "url": "https://github.com/gotenberg/gotenberg/security/advisories/GHSA-7v3r-m9c8-r855"
          },
          {
            "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
            "tags": [
              "Exploit",
              "Vendor Advisory"
            ],
            "url": "https://github.com/gotenberg/gotenberg/security/advisories/GHSA-7v3r-m9c8-r855"
          }
        ],
        "sourceIdentifier": "security-advisories@github.com",
        "vulnStatus": "Analyzed",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-184"
              }
            ],
            "source": "security-advisories@github.com",
            "type": "Secondary"
          }
        ]
      }
    },
    "redhat_vex": {
      "current_release_date": "2026-05-15T19:57:08+00:00",
      "cve": "CVE-2026-42590",
      "id": "CVE-2026-42590",
      "initial_release_date": "2026-01-01T00:00:00+00:00",
      "product_status:known_not_affected": "1",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "Gotenberg: ExifTool group-prefix syntax bypasses dangerous-tag blocklist",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42590.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "important",
      "current_release_date": "2026-07-30T16:52:27Z",
      "cve": "CVE-2026-42590",
      "id": "CVE-2026-42590",
      "initial_release_date": "2026-07-30T16:52:27Z",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-42590",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-42590.json",
      "version": "2"
    },
    "vulnrichment": {
      "containers": {
        "adp": [
          {
            "metrics": [
              {
                "other": {
                  "content": {
                    "id": "CVE-2026-42590",
                    "options": [
                      {
                        "Exploitation": "poc"
                      },
                      {
                        "Automatable": "yes"
                      },
                      {
                        "Technical Impact": "partial"
                      }
                    ],
                    "role": "CISA Coordinator",
                    "timestamp": "2026-05-15T15:57:03.096551Z",
                    "version": "2.0.3"
                  },
                  "type": "ssvc"
                }
              }
            ],
            "providerMetadata": {
              "dateUpdated": "2026-05-15T15:56:45.521Z",
              "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "shortName": "CISA-ADP"
            },
            "references": [
              {
                "tags": [
                  "exploit"
                ],
                "url": "https://github.com/gotenberg/gotenberg/security/advisories/GHSA-7v3r-m9c8-r855"
              }
            ],
            "title": "CISA ADP Vulnrichment"
          }
        ],
        "cna": {
          "affected": [
            {
              "product": "gotenberg",
              "vendor": "gotenberg",
              "versions": [
                {
                  "status": "affected",
                  "version": "\u003c 8.30.0"
                }
              ]
            }
          ],
          "descriptions": [
            {
              "lang": "en",
              "value": "Gotenberg is a Docker-powered stateless API for PDF files. Prior to 8.30.0, The ExifTool metadata write blocklist in Gotenberg can be bypassed using ExifTool\u0027s group-prefix syntax, enabling arbitrary file rename, move, hardlink, and symlink creation on the server. ExifTool supports group-prefix syntax where File:FileName is processed identically to FileName -- the prefix is stripped by SetNewValue in Writer.pl before tag matching. The safeKeyPattern regex (^[a-zA-Z0-9\\-_.:]+$) allows colons, so prefixed tag names pass validation. Any prefix works: File:FileName, System:Directory, a:HardLink, etc. Additionally, FilePermissions, FileUserID, and FileGroupID pseudo-tags are not blocked at all and can modify file attributes without any prefix. This vulnerability is fixed in 8.30.0."
            }
          ],
          "metrics": [
            {
              "cvssV3_1": {
                "attackComplexity": "LOW",
                "attackVector": "NETWORK",
                "availabilityImpact": "LOW",
                "baseScore": 8.2,
                "baseSeverity": "HIGH",
                "confidentialityImpact": "NONE",
                "integrityImpact": "HIGH",
                "privilegesRequired": "NONE",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L",
                "version": "3.1"
              }
            }
          ],
          "problemTypes": [
            {
              "descriptions": [
                {
                  "cweId": "CWE-184",
                  "description": "CWE-184: Incomplete List of Disallowed Inputs",
                  "lang": "en",
                  "type": "CWE"
                }
              ]
            }
          ],
          "providerMetadata": {
            "dateUpdated": "2026-05-14T15:36:30.386Z",
            "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
            "shortName": "GitHub_M"
          },
          "references": [
            {
              "name": "https://github.com/gotenberg/gotenberg/security/advisories/GHSA-7v3r-m9c8-r855",
              "tags": [
                "x_refsource_CONFIRM"
              ],
              "url": "https://github.com/gotenberg/gotenberg/security/advisories/GHSA-7v3r-m9c8-r855"
            }
          ],
          "source": {
            "advisory": "GHSA-7v3r-m9c8-r855",
            "discovery": "UNKNOWN"
          },
          "title": "Gotenberg: ExifTool group-prefix syntax bypasses dangerous-tag blocklist"
        }
      },
      "cveMetadata": {
        "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "assignerShortName": "GitHub_M",
        "cveId": "CVE-2026-42590",
        "datePublished": "2026-05-14T15:36:30.386Z",
        "dateReserved": "2026-04-29T00:31:15.724Z",
        "dateUpdated": "2026-05-15T15:57:55.433Z",
        "state": "PUBLISHED"
      },
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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.


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.