CVE-2026-21872 (GCVE-0-2026-21872)

Vulnerability from cvelistv5 – Published: 2026-01-08 09:50 – Updated: 2026-01-08 15:13
VLAI
Title
NiceGUI apps are vulnerable to XSS which uses `ui.sub_pages` and render arbitrary user-provided links
Summary
NiceGUI is a Python-based UI framework. From versions 2.22.0 to 3.4.1, an unsafe implementation in the click event listener used by ui.sub_pages, combined with attacker-controlled link rendering on the page, causes XSS when the user actively clicks on the link. This issue has been patched in version 3.5.0.
Severity
6.1 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
SSVC
Exploitation: poc Automatable: no Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
  • CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Assigner
References
Impacted products
Vendor Product Version
zauberzeug nicegui Affected: >= 2.22.0, < 3.5.0
Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-21872",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-01-08T15:12:53.988468Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-01-08T15:13:11.652Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "nicegui",
          "vendor": "zauberzeug",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 2.22.0, \u003c 3.5.0"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "NiceGUI is a Python-based UI framework. From versions 2.22.0 to 3.4.1, an unsafe implementation in the click event listener used by ui.sub_pages, combined with attacker-controlled link rendering on the page, causes XSS when the user actively clicks on the link. This issue has been patched in version 3.5.0."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 6.1,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "LOW",
            "integrityImpact": "LOW",
            "privilegesRequired": "NONE",
            "scope": "CHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-79",
              "description": "CWE-79: Improper Neutralization of Input During Web Page Generation (\u0027Cross-site Scripting\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-01-08T09:50:02.801Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/zauberzeug/nicegui/security/advisories/GHSA-m7j5-rq9j-6jj9",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/zauberzeug/nicegui/security/advisories/GHSA-m7j5-rq9j-6jj9"
        },
        {
          "name": "https://github.com/zauberzeug/nicegui/releases/tag/v3.5.0",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/zauberzeug/nicegui/releases/tag/v3.5.0"
        }
      ],
      "source": {
        "advisory": "GHSA-m7j5-rq9j-6jj9",
        "discovery": "UNKNOWN"
      },
      "title": "NiceGUI apps are vulnerable to XSS which uses `ui.sub_pages` and render arbitrary user-provided links"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-21872",
    "datePublished": "2026-01-08T09:50:02.801Z",
    "dateReserved": "2026-01-05T16:44:16.369Z",
    "dateUpdated": "2026-01-08T15:13:11.652Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-21872",
      "date": "2026-06-30",
      "epss": "0.00238",
      "percentile": "0.14721"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-21872\",\"sourceIdentifier\":\"security-advisories@github.com\",\"published\":\"2026-01-08T10:15:55.470\",\"lastModified\":\"2026-06-17T10:19:03.980\",\"vulnStatus\":\"Analyzed\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"NiceGUI is a Python-based UI framework. From versions 2.22.0 to 3.4.1, an unsafe implementation in the click event listener used by ui.sub_pages, combined with attacker-controlled link rendering on the page, causes XSS when the user actively clicks on the link. This issue has been patched in version 3.5.0.\"},{\"lang\":\"es\",\"value\":\"NiceGUI es un framework de interfaz de usuario (UI) basado en Python. Desde las versiones 2.22.0 hasta la 3.4.1, una implementaci\u00f3n insegura en el oyente de eventos de clic utilizado por ui.sub_pages, combinada con la renderizaci\u00f3n de enlaces controlada por el atacante en la p\u00e1gina, causa XSS cuando el usuario hace clic activamente en el enlace. Este problema ha sido parcheado en la versi\u00f3n 3.5.0.\"}],\"affected\":[{\"source\":\"security-advisories@github.com\",\"affectedData\":[{\"vendor\":\"zauberzeug\",\"product\":\"nicegui\",\"versions\":[{\"version\":\"\u003e= 2.22.0, \u003c 3.5.0\",\"status\":\"affected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N\",\"baseScore\":6.1,\"baseSeverity\":\"MEDIUM\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"REQUIRED\",\"scope\":\"CHANGED\",\"confidentialityImpact\":\"LOW\",\"integrityImpact\":\"LOW\",\"availabilityImpact\":\"NONE\"},\"exploitabilityScore\":2.8,\"impactScore\":2.7}],\"ssvcV203\":[{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"ssvcData\":{\"timestamp\":\"2026-01-08T15:12:53.988468Z\",\"id\":\"CVE-2026-21872\",\"options\":[{\"exploitation\":\"poc\"},{\"automatable\":\"no\"},{\"technicalImpact\":\"partial\"}],\"role\":\"CISA Coordinator\",\"version\":\"2.0.3\"}}]},\"weaknesses\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-79\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:zauberzeug:nicegui:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"2.22.0\",\"versionEndExcluding\":\"3.5.0\",\"matchCriteriaId\":\"37903F79-6269-4F0A-939A-36F3E3CC41B3\"}]}]}],\"references\":[{\"url\":\"https://github.com/zauberzeug/nicegui/releases/tag/v3.5.0\",\"source\":\"security-advisories@github.com\",\"tags\":[\"Release Notes\"]},{\"url\":\"https://github.com/zauberzeug/nicegui/security/advisories/GHSA-m7j5-rq9j-6jj9\",\"source\":\"security-advisories@github.com\",\"tags\":[\"Exploit\",\"Vendor Advisory\"]}]}}",
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-21872\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"poc\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-01-08T15:12:53.988468Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-01-08T15:13:00.614Z\"}}], \"cna\": {\"title\": \"NiceGUI apps are vulnerable to XSS which uses `ui.sub_pages` and render arbitrary user-provided links\", \"source\": {\"advisory\": \"GHSA-m7j5-rq9j-6jj9\", \"discovery\": \"UNKNOWN\"}, \"metrics\": [{\"cvssV3_1\": {\"scope\": \"CHANGED\", \"version\": \"3.1\", \"baseScore\": 6.1, \"attackVector\": \"NETWORK\", \"baseSeverity\": \"MEDIUM\", \"vectorString\": \"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N\", \"integrityImpact\": \"LOW\", \"userInteraction\": \"REQUIRED\", \"attackComplexity\": \"LOW\", \"availabilityImpact\": \"NONE\", \"privilegesRequired\": \"NONE\", \"confidentialityImpact\": \"LOW\"}}], \"affected\": [{\"vendor\": \"zauberzeug\", \"product\": \"nicegui\", \"versions\": [{\"status\": \"affected\", \"version\": \"\u003e= 2.22.0, \u003c 3.5.0\"}]}], \"references\": [{\"url\": \"https://github.com/zauberzeug/nicegui/security/advisories/GHSA-m7j5-rq9j-6jj9\", \"name\": \"https://github.com/zauberzeug/nicegui/security/advisories/GHSA-m7j5-rq9j-6jj9\", \"tags\": [\"x_refsource_CONFIRM\"]}, {\"url\": \"https://github.com/zauberzeug/nicegui/releases/tag/v3.5.0\", \"name\": \"https://github.com/zauberzeug/nicegui/releases/tag/v3.5.0\", \"tags\": [\"x_refsource_MISC\"]}], \"descriptions\": [{\"lang\": \"en\", \"value\": \"NiceGUI is a Python-based UI framework. From versions 2.22.0 to 3.4.1, an unsafe implementation in the click event listener used by ui.sub_pages, combined with attacker-controlled link rendering on the page, causes XSS when the user actively clicks on the link. This issue has been patched in version 3.5.0.\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-79\", \"description\": \"CWE-79: Improper Neutralization of Input During Web Page Generation (\u0027Cross-site Scripting\u0027)\"}]}], \"providerMetadata\": {\"orgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"shortName\": \"GitHub_M\", \"dateUpdated\": \"2026-01-08T09:50:02.801Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-21872\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-01-08T15:13:11.652Z\", \"dateReserved\": \"2026-01-05T16:44:16.369Z\", \"assignerOrgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"datePublished\": \"2026-01-08T09:50:02.801Z\", \"assignerShortName\": \"GitHub_M\"}",
      "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.