CVE-2026-29186 (GCVE-0-2026-29186)
Vulnerability from cvelistv5
Published
2026-03-07 15:03
Modified
2026-07-15 01:10
CWE
  • CWE-434 - Unrestricted Upload of File with Dangerous Type
  • CWE-74 - Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
Summary
Backstage is an open framework for building developer portals. Prior to version 1.14.3, this is a configuration bypass vulnerability that enables arbitrary code execution. The @backstage/plugin-techdocs-node package uses an allowlist to filter dangerous MkDocs configuration keys during the documentation build process. A gap in this allowlist allows attackers to craft an mkdocs.yml that causes arbitrary Python code execution, completely bypassing TechDocs' security controls. This issue has been patched in version 1.14.3.
Impacted products
Vendor Product Version
backstage backstage Version: < 1.14.3
Create a notification for this product.
Show details on NVD website


{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-29186",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-03-09T20:15:04.131913Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-03-09T20:24:16.895Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      },
      {
        "affected": [
          {
            "collectionURL": "https://catalog.redhat.com/software/containers/",
            "cpes": [
              "cpe:/a:redhat:rhdh:1.8::el9"
            ],
            "defaultStatus": "affected",
            "packageName": "rhdh/rhdh-hub-rhel9",
            "product": "Red Hat Developer Hub 1.8",
            "vendor": "Red Hat",
            "versions": [
              {
                "lessThan": "*",
                "status": "unaffected",
                "version": "1776784286",
                "versionType": "rpm"
              }
            ]
          },
          {
            "collectionURL": "https://catalog.redhat.com/software/containers/",
            "cpes": [
              "cpe:/a:redhat:rhdh:1.9::el9"
            ],
            "defaultStatus": "affected",
            "packageName": "rhdh/rhdh-hub-rhel9",
            "product": "Red Hat Developer Hub 1.9",
            "vendor": "Red Hat",
            "versions": [
              {
                "lessThan": "*",
                "status": "unaffected",
                "version": "1777903262",
                "versionType": "rpm"
              }
            ]
          },
          {
            "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
            "cpes": [
              "cpe:/a:redhat:ansible_portal:2"
            ],
            "defaultStatus": "affected",
            "packageName": "ansible-automation-platform/automation-portal",
            "product": "Self-service automation portal 2",
            "vendor": "Red Hat"
          }
        ],
        "datePublic": "2026-03-07T15:03:51.422Z",
        "descriptions": [
          {
            "lang": "en",
            "value": "A flaw was found in Backstage. The backstage/plugin-techdocs-node package uses an allowlist to filter dangerous MkDocs configuration keys during the documentation build process. A gap in this allowlist allows attackers to craft an mkdocs.yml file that causes arbitrary Python code execution."
          }
        ],
        "metrics": [
          {
            "other": {
              "content": {
                "namespace": "https://access.redhat.com/security/updates/classification/",
                "value": "Important"
              },
              "type": "Red Hat severity rating"
            }
          },
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "NETWORK",
              "availabilityImpact": "LOW",
              "baseScore": 9.1,
              "baseSeverity": "CRITICAL",
              "confidentialityImpact": "HIGH",
              "integrityImpact": "LOW",
              "privilegesRequired": "LOW",
              "scope": "CHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:L",
              "version": "3.1"
            },
            "format": "CVSS"
          }
        ],
        "problemTypes": [
          {
            "descriptions": [
              {
                "cweId": "CWE-791",
                "description": "Incomplete Filtering of Special Elements",
                "lang": "en",
                "type": "CWE"
              }
            ]
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-07-15T01:10:31.895Z",
          "orgId": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c",
          "shortName": "redhat-SADP"
        },
        "references": [
          {
            "tags": [
              "vdb-entry",
              "x_refsource_REDHAT"
            ],
            "url": "https://access.redhat.com/security/cve/CVE-2026-29186"
          },
          {
            "name": "RHBZ#2445480",
            "tags": [
              "issue-tracking",
              "x_refsource_REDHAT"
            ],
            "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2445480"
          },
          {
            "tags": [
              "x_sadp-csaf-vex"
            ],
            "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-29186.json"
          },
          {
            "tags": [
              "vendor-advisory",
              "x_refsource_REDHAT"
            ],
            "url": "https://access.redhat.com/errata/RHSA-2026:9742"
          },
          {
            "tags": [
              "vendor-advisory",
              "x_refsource_REDHAT"
            ],
            "url": "https://access.redhat.com/errata/RHSA-2026:13826"
          }
        ],
        "solutions": [
          {
            "lang": "en",
            "value": "RHSA-2026:9742: Red Hat Developer Hub 1.8"
          },
          {
            "lang": "en",
            "value": "RHSA-2026:13826: Red Hat Developer Hub 1.9"
          }
        ],
        "timeline": [
          {
            "lang": "en",
            "time": "2026-03-07T16:01:40.949Z",
            "value": "Reported to Red Hat."
          },
          {
            "lang": "en",
            "time": "2026-03-07T15:03:51.422Z",
            "value": "Made public."
          }
        ],
        "title": "backstage/plugin-techdocs-node: TechDocs Mkdocs configuration key enables arbitrary code execution",
        "workarounds": [
          {
            "lang": "en",
            "value": "To mitigate this issue, enable docker isolation by updating the Backstage configuration to use \u0027runIn: docker\u0027 instead of \u0027runIn: local\u0027, confining the arbitrary Python code execution to a containerized environment. Additionally, limit commit access to repositories tracked by Backstage to trusted contributors only, and enforce mandatory pull request (PR) reviews for any modifications made to the mkdocs.yml file."
          }
        ],
        "x_adpType": "supplier",
        "x_generator": {
          "engine": "sadp-cli 1.0.0"
        }
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "backstage",
          "vendor": "backstage",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 1.14.3"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Backstage is an open framework for building developer portals. Prior to version 1.14.3, this is a configuration bypass vulnerability that enables arbitrary code execution. The @backstage/plugin-techdocs-node package uses an allowlist to filter dangerous MkDocs configuration keys during the documentation build process. A gap in this allowlist allows attackers to craft an mkdocs.yml that causes arbitrary Python code execution, completely bypassing TechDocs\u0027 security controls. This issue has been patched in version 1.14.3."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "LOW",
            "baseScore": 7.7,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "LOW",
            "privilegesRequired": "LOW",
            "scope": "CHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:L",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-434",
              "description": "CWE-434: Unrestricted Upload of File with Dangerous Type",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-74",
              "description": "CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component (\u0027Injection\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-03-07T15:03:51.422Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/backstage/backstage/security/advisories/GHSA-928r-fm4v-mvrw",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/backstage/backstage/security/advisories/GHSA-928r-fm4v-mvrw"
        }
      ],
      "source": {
        "advisory": "GHSA-928r-fm4v-mvrw",
        "discovery": "UNKNOWN"
      },
      "title": "@backstage/plugin-techdocs-node: TechDocs Mkdocs Configuration Key Enables Arbitrary Code Execution"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-29186",
    "datePublished": "2026-03-07T15:03:51.422Z",
    "dateReserved": "2026-03-04T14:44:00.714Z",
    "dateUpdated": "2026-07-15T01:10:31.895Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-29186\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"total\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-03-09T20:15:04.131913Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-03-09T20:15:47.537Z\"}}], \"cna\": {\"title\": \"@backstage/plugin-techdocs-node: TechDocs Mkdocs Configuration Key Enables Arbitrary Code Execution\", \"source\": {\"advisory\": \"GHSA-928r-fm4v-mvrw\", \"discovery\": \"UNKNOWN\"}, \"metrics\": [{\"cvssV3_1\": {\"scope\": \"CHANGED\", \"version\": \"3.1\", \"baseScore\": 7.7, \"attackVector\": \"NETWORK\", \"baseSeverity\": \"HIGH\", \"vectorString\": \"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:L\", \"integrityImpact\": \"LOW\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"HIGH\", \"availabilityImpact\": \"LOW\", \"privilegesRequired\": \"LOW\", \"confidentialityImpact\": \"HIGH\"}}], \"affected\": [{\"vendor\": \"backstage\", \"product\": \"backstage\", \"versions\": [{\"status\": \"affected\", \"version\": \"\u003c 1.14.3\"}]}], \"references\": [{\"url\": \"https://github.com/backstage/backstage/security/advisories/GHSA-928r-fm4v-mvrw\", \"name\": \"https://github.com/backstage/backstage/security/advisories/GHSA-928r-fm4v-mvrw\", \"tags\": [\"x_refsource_CONFIRM\"]}], \"descriptions\": [{\"lang\": \"en\", \"value\": \"Backstage is an open framework for building developer portals. Prior to version 1.14.3, this is a configuration bypass vulnerability that enables arbitrary code execution. The @backstage/plugin-techdocs-node package uses an allowlist to filter dangerous MkDocs configuration keys during the documentation build process. A gap in this allowlist allows attackers to craft an mkdocs.yml that causes arbitrary Python code execution, completely bypassing TechDocs\u0027 security controls. This issue has been patched in version 1.14.3.\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-434\", \"description\": \"CWE-434: Unrestricted Upload of File with Dangerous Type\"}]}, {\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-74\", \"description\": \"CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component (\u0027Injection\u0027)\"}]}], \"providerMetadata\": {\"orgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"shortName\": \"GitHub_M\", \"dateUpdated\": \"2026-03-07T15:03:51.422Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-29186\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-03-09T20:24:16.895Z\", \"dateReserved\": \"2026-03-04T14:44:00.714Z\", \"assignerOrgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"datePublished\": \"2026-03-07T15:03:51.422Z\", \"assignerShortName\": \"GitHub_M\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.


Loading…

Loading…

Loading…

Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
  • Confirmed: The vulnerability is confirmed from an analyst perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
  • Patched: This vulnerability was successfully patched by the user reporting the sighting.
  • Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
  • Not confirmed: The user expresses doubt about the veracity of the vulnerability.
  • Not patched: This vulnerability was not successfully patched by the user reporting the sighting.


Loading…

Loading…