CVE-2026-109288 (GCVE-0-2026-109288)

Vulnerability from cvelistv5 – Published: 2026-10-12 16:04 – Updated: 2026-10-13 15:39
VLAI
Title
Open WebUI before 0.11.4 Stored XSS via javascript: URLs in Markdown Links
Summary
Open WebUI before 0.11.4 contains a stored cross-site scripting vulnerability in MarkdownInlineTokens.svelte, which renders markdown link URLs into anchor hrefs without validating their scheme. Authenticated users can embed javascript: links in shared chats that, when clicked by a victim, steal the victim's JWT from local storage, including admins' tokens.
Severity
7.2 (High)
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
6.4 (Medium)
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:N
SSVC
Exploitation: poc Automatable: no Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-10-13 15:39 UTC
CWE
  • CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Assigner
VulnCheck CNA under the mitre root
CNA scorecard B 84/100 over 6045 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
open-webui open-webui Affected: 0 , < 0.11.4 (semver)
Unaffected: 0.11.4 (semver)
    cpe:2.3:a:openwebui:open_webui:*:*:*:*:*:*:*:*
Create a notification for this product.
Date Public
2026-09-27 00:00
Credits
r20z19 Classic298
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-109288",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-10-13T15:39:15.981425Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-10-13T15:39:33.693Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "exploit"
            ],
            "url": "https://github.com/open-webui/open-webui/security/advisories/GHSA-wf9m-46cp-c6h6"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "packageURL": "pkg:pypi/open-webui",
          "product": "open-webui",
          "vendor": "open-webui",
          "versions": [
            {
              "lessThan": "0.11.4",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "0.11.4",
              "versionType": "semver"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:a:openwebui:open_webui:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "0.11.4",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "reporter",
          "value": "r20z19"
        },
        {
          "lang": "en",
          "type": "finder",
          "value": "Classic298"
        }
      ],
      "datePublic": "2026-09-27T00:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "value": "Open WebUI before 0.11.4 contains a stored cross-site scripting vulnerability in MarkdownInlineTokens.svelte, which renders markdown link URLs into anchor hrefs without validating their scheme. Authenticated users can embed javascript: links in shared chats that, when clicked by a victim, steal the victim\u0027s JWT from local storage, including admins\u0027 tokens."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "attackVector": "NETWORK",
            "baseScore": 7.2,
            "baseSeverity": "HIGH",
            "privilegesRequired": "LOW",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "ACTIVE",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "HIGH"
          },
          "format": "CVSS"
        },
        {
          "cvssV3_1": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 6.4,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:N",
            "version": "3.1"
          },
          "format": "CVSS"
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-79",
              "description": "Improper Neutralization of Input During Web Page Generation (\u0027Cross-site Scripting\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-12T16:04:50.352Z",
        "orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
        "shortName": "VulnCheck"
      },
      "references": [
        {
          "name": "GitHub Security Advisory (GHSA-wf9m-46cp-c6h6)",
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://github.com/open-webui/open-webui/security/advisories/GHSA-wf9m-46cp-c6h6"
        },
        {
          "name": "VulnCheck Advisory: Open WebUI before 0.11.4 Stored XSS via javascript: URLs in Markdown Links",
          "tags": [
            "third-party-advisory"
          ],
          "url": "https://www.vulncheck.com/advisories/open-webui-before-0.11.4-stored-xss-via-javascript-urls-in-markdown-links"
        }
      ],
      "title": "Open WebUI before 0.11.4 Stored XSS via javascript: URLs in Markdown Links",
      "x_generator": {
        "engine": "vulncheck-endgame"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
    "assignerShortName": "VulnCheck",
    "cveId": "CVE-2026-109288",
    "datePublished": "2026-10-12T16:04:50.352Z",
    "dateReserved": "2026-10-12T14:12:52.833Z",
    "dateUpdated": "2026-10-13T15:39:33.693Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-109288",
      "date": "2026-10-14",
      "epss": "0.00231",
      "percentile": "0.12977"
    },
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "defaultStatus": "unaffected",
                "packageURL": "pkg:pypi/open-webui",
                "product": "open-webui",
                "vendor": "open-webui",
                "versions": [
                  {
                    "lessThan": "0.11.4",
                    "status": "affected",
                    "version": "0",
                    "versionType": "semver"
                  },
                  {
                    "status": "unaffected",
                    "version": "0.11.4",
                    "versionType": "semver"
                  }
                ]
              }
            ],
            "source": "disclosure@vulncheck.com"
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "Open WebUI before 0.11.4 contains a stored cross-site scripting vulnerability in MarkdownInlineTokens.svelte, which renders markdown link URLs into anchor hrefs without validating their scheme. Authenticated users can embed javascript: links in shared chats that, when clicked by a victim, steal the victim\u0027s JWT from local storage, including admins\u0027 tokens."
          }
        ],
        "id": "CVE-2026-109288",
        "lastModified": "2026-10-13T20:39:48.767",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "HIGH",
                "attackVector": "NETWORK",
                "availabilityImpact": "NONE",
                "baseScore": 6.4,
                "baseSeverity": "MEDIUM",
                "confidentialityImpact": "HIGH",
                "integrityImpact": "HIGH",
                "privilegesRequired": "LOW",
                "scope": "UNCHANGED",
                "userInteraction": "REQUIRED",
                "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:N",
                "version": "3.1"
              },
              "exploitabilityScore": 1.2,
              "impactScore": 5.2,
              "source": "disclosure@vulncheck.com",
              "type": "Secondary"
            }
          ],
          "cvssMetricV40": [
            {
              "cvssData": {
                "Automatable": "NOT_DEFINED",
                "Recovery": "NOT_DEFINED",
                "Safety": "NOT_DEFINED",
                "attackComplexity": "LOW",
                "attackRequirements": "PRESENT",
                "attackVector": "NETWORK",
                "availabilityRequirement": "NOT_DEFINED",
                "baseScore": 7.2,
                "baseSeverity": "HIGH",
                "confidentialityRequirement": "NOT_DEFINED",
                "exploitMaturity": "NOT_DEFINED",
                "integrityRequirement": "NOT_DEFINED",
                "modifiedAttackComplexity": "NOT_DEFINED",
                "modifiedAttackRequirements": "NOT_DEFINED",
                "modifiedAttackVector": "NOT_DEFINED",
                "modifiedPrivilegesRequired": "NOT_DEFINED",
                "modifiedSubAvailabilityImpact": "NOT_DEFINED",
                "modifiedSubConfidentialityImpact": "NOT_DEFINED",
                "modifiedSubIntegrityImpact": "NOT_DEFINED",
                "modifiedUserInteraction": "NOT_DEFINED",
                "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
                "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
                "modifiedVulnIntegrityImpact": "NOT_DEFINED",
                "privilegesRequired": "LOW",
                "providerUrgency": "NOT_DEFINED",
                "subAvailabilityImpact": "NONE",
                "subConfidentialityImpact": "NONE",
                "subIntegrityImpact": "NONE",
                "userInteraction": "ACTIVE",
                "valueDensity": "NOT_DEFINED",
                "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
                "version": "4.0",
                "vulnAvailabilityImpact": "NONE",
                "vulnConfidentialityImpact": "HIGH",
                "vulnIntegrityImpact": "HIGH",
                "vulnerabilityResponseEffort": "NOT_DEFINED"
              },
              "source": "disclosure@vulncheck.com",
              "type": "Secondary"
            }
          ],
          "ssvcV203": [
            {
              "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "ssvcData": {
                "id": "CVE-2026-109288",
                "options": [
                  {
                    "exploitation": "poc"
                  },
                  {
                    "automatable": "no"
                  },
                  {
                    "technicalImpact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-10-13T15:39:15.981425Z",
                "version": "2.0.3"
              }
            }
          ]
        },
        "published": "2026-10-12T17:17:21.913",
        "references": [
          {
            "source": "disclosure@vulncheck.com",
            "url": "https://github.com/open-webui/open-webui/security/advisories/GHSA-wf9m-46cp-c6h6"
          },
          {
            "source": "disclosure@vulncheck.com",
            "url": "https://www.vulncheck.com/advisories/open-webui-before-0.11.4-stored-xss-via-javascript-urls-in-markdown-links"
          },
          {
            "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
            "url": "https://github.com/open-webui/open-webui/security/advisories/GHSA-wf9m-46cp-c6h6"
          }
        ],
        "sourceIdentifier": "disclosure@vulncheck.com",
        "vulnStatus": "Awaiting Analysis",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-79"
              }
            ],
            "source": "disclosure@vulncheck.com",
            "type": "Secondary"
          }
        ]
      }
    },
    "vulnrichment": {
      "containers": {
        "adp": [
          {
            "metrics": [
              {
                "other": {
                  "content": {
                    "id": "CVE-2026-109288",
                    "options": [
                      {
                        "Exploitation": "poc"
                      },
                      {
                        "Automatable": "no"
                      },
                      {
                        "Technical Impact": "total"
                      }
                    ],
                    "role": "CISA Coordinator",
                    "timestamp": "2026-10-13T15:39:15.981425Z",
                    "version": "2.0.3"
                  },
                  "type": "ssvc"
                }
              }
            ],
            "providerMetadata": {
              "dateUpdated": "2026-10-13T15:39:28.015Z",
              "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "shortName": "CISA-ADP"
            },
            "references": [
              {
                "tags": [
                  "exploit"
                ],
                "url": "https://github.com/open-webui/open-webui/security/advisories/GHSA-wf9m-46cp-c6h6"
              }
            ],
            "title": "CISA ADP Vulnrichment"
          }
        ],
        "cna": {
          "affected": [
            {
              "defaultStatus": "unaffected",
              "packageURL": "pkg:pypi/open-webui",
              "product": "open-webui",
              "vendor": "open-webui",
              "versions": [
                {
                  "lessThan": "0.11.4",
                  "status": "affected",
                  "version": "0",
                  "versionType": "semver"
                },
                {
                  "status": "unaffected",
                  "version": "0.11.4",
                  "versionType": "semver"
                }
              ]
            }
          ],
          "cpeApplicability": [
            {
              "nodes": [
                {
                  "cpeMatch": [
                    {
                      "criteria": "cpe:2.3:a:openwebui:open_webui:*:*:*:*:*:*:*:*",
                      "versionEndExcluding": "0.11.4",
                      "vulnerable": true
                    }
                  ],
                  "negate": false,
                  "operator": "OR"
                }
              ]
            }
          ],
          "credits": [
            {
              "lang": "en",
              "type": "reporter",
              "value": "r20z19"
            },
            {
              "lang": "en",
              "type": "finder",
              "value": "Classic298"
            }
          ],
          "datePublic": "2026-09-27T00:00:00.000Z",
          "descriptions": [
            {
              "lang": "en",
              "value": "Open WebUI before 0.11.4 contains a stored cross-site scripting vulnerability in MarkdownInlineTokens.svelte, which renders markdown link URLs into anchor hrefs without validating their scheme. Authenticated users can embed javascript: links in shared chats that, when clicked by a victim, steal the victim\u0027s JWT from local storage, including admins\u0027 tokens."
            }
          ],
          "metrics": [
            {
              "cvssV4_0": {
                "attackComplexity": "LOW",
                "attackRequirements": "PRESENT",
                "attackVector": "NETWORK",
                "baseScore": 7.2,
                "baseSeverity": "HIGH",
                "privilegesRequired": "LOW",
                "subAvailabilityImpact": "NONE",
                "subConfidentialityImpact": "NONE",
                "subIntegrityImpact": "NONE",
                "userInteraction": "ACTIVE",
                "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N",
                "version": "4.0",
                "vulnAvailabilityImpact": "NONE",
                "vulnConfidentialityImpact": "HIGH",
                "vulnIntegrityImpact": "HIGH"
              },
              "format": "CVSS"
            },
            {
              "cvssV3_1": {
                "attackComplexity": "HIGH",
                "attackVector": "NETWORK",
                "availabilityImpact": "NONE",
                "baseScore": 6.4,
                "baseSeverity": "MEDIUM",
                "confidentialityImpact": "HIGH",
                "integrityImpact": "HIGH",
                "privilegesRequired": "LOW",
                "scope": "UNCHANGED",
                "userInteraction": "REQUIRED",
                "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:N",
                "version": "3.1"
              },
              "format": "CVSS"
            }
          ],
          "problemTypes": [
            {
              "descriptions": [
                {
                  "cweId": "CWE-79",
                  "description": "Improper Neutralization of Input During Web Page Generation (\u0027Cross-site Scripting\u0027)",
                  "lang": "en",
                  "type": "CWE"
                }
              ]
            }
          ],
          "providerMetadata": {
            "dateUpdated": "2026-10-12T16:04:50.352Z",
            "orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
            "shortName": "VulnCheck"
          },
          "references": [
            {
              "name": "GitHub Security Advisory (GHSA-wf9m-46cp-c6h6)",
              "tags": [
                "vendor-advisory"
              ],
              "url": "https://github.com/open-webui/open-webui/security/advisories/GHSA-wf9m-46cp-c6h6"
            },
            {
              "name": "VulnCheck Advisory: Open WebUI before 0.11.4 Stored XSS via javascript: URLs in Markdown Links",
              "tags": [
                "third-party-advisory"
              ],
              "url": "https://www.vulncheck.com/advisories/open-webui-before-0.11.4-stored-xss-via-javascript-urls-in-markdown-links"
            }
          ],
          "title": "Open WebUI before 0.11.4 Stored XSS via javascript: URLs in Markdown Links",
          "x_generator": {
            "engine": "vulncheck-endgame"
          }
        }
      },
      "cveMetadata": {
        "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
        "assignerShortName": "VulnCheck",
        "cveId": "CVE-2026-109288",
        "datePublished": "2026-10-12T16:04:50.352Z",
        "dateReserved": "2026-10-12T14:12:52.833Z",
        "dateUpdated": "2026-10-12T16:04:50.352Z",
        "state": "PUBLISHED"
      },
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.

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.
Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

JSON

Loading timeline…




    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.