CVE-2026-33335 (GCVE-0-2026-33335)

Vulnerability from cvelistv5 – Published: 2026-03-24 15:07 – Updated: 2026-03-25 13:41
VLAI
Title
Vikunja Desktop allows arbitrary local application invocation via unvalidated shell.openExternal
Summary
Vikunja is an open-source self-hosted task management platform. Starting in version 0.21.0 and prior to version 2.2.0, the Vikunja Desktop Electron wrapper passes URLs from `window.open()` calls directly to `shell.openExternal()` without any validation or protocol allowlisting. An attacker who can place a link with `target="_blank"` (or that otherwise triggers `window.open`) in user-generated content can cause the victim's operating system to open arbitrary URI schemes, invoking local applications, opening local files, or triggering custom protocol handlers. Version 2.2.0 patches the issue.
Severity
6.4 (Medium)
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:H/SI:H/SA:H
SSVC
Exploitation: poc Automatable: no Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
  • CWE-939 - Improper Authorization in Handler for Custom URL Scheme
Assigner
References
Impacted products
Vendor Product Version
go-vikunja vikunja Affected: >= 0.21.0, < 2.2.0
Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-33335",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-03-25T13:41:45.712476Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-03-25T13:41:50.096Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "exploit"
            ],
            "url": "https://github.com/go-vikunja/vikunja/security/advisories/GHSA-6q44-85gc-cjvf"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "vikunja",
          "vendor": "go-vikunja",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 0.21.0, \u003c 2.2.0"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Vikunja is an open-source self-hosted task management platform. Starting in version 0.21.0 and prior to version 2.2.0, the Vikunja Desktop Electron wrapper passes URLs from `window.open()` calls directly to `shell.openExternal()` without any validation or protocol allowlisting. An attacker who can place a link with `target=\"_blank\"` (or that otherwise triggers `window.open`) in user-generated content can cause the victim\u0027s operating system to open arbitrary URI schemes, invoking local applications, opening local files, or triggering custom protocol handlers. Version 2.2.0 patches the issue."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 6.4,
            "baseSeverity": "MEDIUM",
            "privilegesRequired": "LOW",
            "subAvailabilityImpact": "HIGH",
            "subConfidentialityImpact": "HIGH",
            "subIntegrityImpact": "HIGH",
            "userInteraction": "PASSIVE",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:H/SI:H/SA:H",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "NONE",
            "vulnIntegrityImpact": "NONE"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-939",
              "description": "CWE-939: Improper Authorization in Handler for Custom URL Scheme",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-03-24T15:07:41.460Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/go-vikunja/vikunja/security/advisories/GHSA-6q44-85gc-cjvf",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/go-vikunja/vikunja/security/advisories/GHSA-6q44-85gc-cjvf"
        },
        {
          "name": "https://vikunja.io/changelog/vikunja-v2.2.0-was-released",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://vikunja.io/changelog/vikunja-v2.2.0-was-released"
        }
      ],
      "source": {
        "advisory": "GHSA-6q44-85gc-cjvf",
        "discovery": "UNKNOWN"
      },
      "title": "Vikunja Desktop allows arbitrary local application invocation via unvalidated shell.openExternal"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-33335",
    "datePublished": "2026-03-24T15:07:41.460Z",
    "dateReserved": "2026-03-18T22:15:11.812Z",
    "dateUpdated": "2026-03-25T13:41:50.096Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-33335",
      "date": "2026-06-01",
      "epss": "0.00051",
      "percentile": "0.16344"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-33335\",\"sourceIdentifier\":\"security-advisories@github.com\",\"published\":\"2026-03-24T16:16:33.227\",\"lastModified\":\"2026-03-27T16:58:07.513\",\"vulnStatus\":\"Analyzed\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"Vikunja is an open-source self-hosted task management platform. Starting in version 0.21.0 and prior to version 2.2.0, the Vikunja Desktop Electron wrapper passes URLs from `window.open()` calls directly to `shell.openExternal()` without any validation or protocol allowlisting. An attacker who can place a link with `target=\\\"_blank\\\"` (or that otherwise triggers `window.open`) in user-generated content can cause the victim\u0027s operating system to open arbitrary URI schemes, invoking local applications, opening local files, or triggering custom protocol handlers. Version 2.2.0 patches the issue.\"},{\"lang\":\"es\",\"value\":\"Vikunja es una plataforma de gesti\u00f3n de tareas de c\u00f3digo abierto y autoalojada. A partir de la versi\u00f3n 0.21.0 y antes de la versi\u00f3n 2.2.0, el *wrapper* de Electron de Vikunja Desktop pasa las URL de las llamadas a `window.open()` directamente a `shell.openExternal()` sin ninguna validaci\u00f3n o lista blanca de *protocolos*. Un *atacante* que puede colocar un enlace con `target=\\\"_blank\\\"` (o que de otro modo active `window.open`) en contenido generado por el usuario puede hacer que el *sistema operativo* de la v\u00edctima abra esquemas URI arbitrarios, invocando aplicaciones locales, abriendo archivos locales o activando manejadores de *protocolos* personalizados. La versi\u00f3n 2.2.0 corrige el problema.\"}],\"metrics\":{\"cvssMetricV40\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"4.0\",\"vectorString\":\"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:H/SI:H/SA:H/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\",\"baseScore\":6.4,\"baseSeverity\":\"MEDIUM\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"attackRequirements\":\"NONE\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"PASSIVE\",\"vulnConfidentialityImpact\":\"NONE\",\"vulnIntegrityImpact\":\"NONE\",\"vulnAvailabilityImpact\":\"NONE\",\"subConfidentialityImpact\":\"HIGH\",\"subIntegrityImpact\":\"HIGH\",\"subAvailabilityImpact\":\"HIGH\",\"exploitMaturity\":\"NOT_DEFINED\",\"confidentialityRequirement\":\"NOT_DEFINED\",\"integrityRequirement\":\"NOT_DEFINED\",\"availabilityRequirement\":\"NOT_DEFINED\",\"modifiedAttackVector\":\"NOT_DEFINED\",\"modifiedAttackComplexity\":\"NOT_DEFINED\",\"modifiedAttackRequirements\":\"NOT_DEFINED\",\"modifiedPrivilegesRequired\":\"NOT_DEFINED\",\"modifiedUserInteraction\":\"NOT_DEFINED\",\"modifiedVulnConfidentialityImpact\":\"NOT_DEFINED\",\"modifiedVulnIntegrityImpact\":\"NOT_DEFINED\",\"modifiedVulnAvailabilityImpact\":\"NOT_DEFINED\",\"modifiedSubConfidentialityImpact\":\"NOT_DEFINED\",\"modifiedSubIntegrityImpact\":\"NOT_DEFINED\",\"modifiedSubAvailabilityImpact\":\"NOT_DEFINED\",\"Safety\":\"NOT_DEFINED\",\"Automatable\":\"NOT_DEFINED\",\"Recovery\":\"NOT_DEFINED\",\"valueDensity\":\"NOT_DEFINED\",\"vulnerabilityResponseEffort\":\"NOT_DEFINED\",\"providerUrgency\":\"NOT_DEFINED\"}}],\"cvssMetricV31\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H\",\"baseScore\":8.0,\"baseSeverity\":\"HIGH\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"REQUIRED\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":2.1,\"impactScore\":5.9}]},\"weaknesses\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-939\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:vikunja:vikunja:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"0.21.0\",\"versionEndExcluding\":\"2.2.2\",\"matchCriteriaId\":\"AE5EF0A7-C1CA-45D6-9422-16F867671DFF\"}]}]}],\"references\":[{\"url\":\"https://github.com/go-vikunja/vikunja/security/advisories/GHSA-6q44-85gc-cjvf\",\"source\":\"security-advisories@github.com\",\"tags\":[\"Exploit\",\"Vendor Advisory\"]},{\"url\":\"https://vikunja.io/changelog/vikunja-v2.2.0-was-released\",\"source\":\"security-advisories@github.com\",\"tags\":[\"Release Notes\"]},{\"url\":\"https://github.com/go-vikunja/vikunja/security/advisories/GHSA-6q44-85gc-cjvf\",\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"tags\":[\"Exploit\",\"Vendor Advisory\"]}]}}",
    "vulnrichment": {
      "containers": "{\"cna\": {\"title\": \"Vikunja Desktop allows arbitrary local application invocation via unvalidated shell.openExternal\", \"problemTypes\": [{\"descriptions\": [{\"cweId\": \"CWE-939\", \"lang\": \"en\", \"description\": \"CWE-939: Improper Authorization in Handler for Custom URL Scheme\", \"type\": \"CWE\"}]}], \"metrics\": [{\"cvssV4_0\": {\"attackVector\": \"NETWORK\", \"attackComplexity\": \"LOW\", \"attackRequirements\": \"NONE\", \"privilegesRequired\": \"LOW\", \"userInteraction\": \"PASSIVE\", \"vulnConfidentialityImpact\": \"NONE\", \"vulnIntegrityImpact\": \"NONE\", \"vulnAvailabilityImpact\": \"NONE\", \"subConfidentialityImpact\": \"HIGH\", \"subIntegrityImpact\": \"HIGH\", \"subAvailabilityImpact\": \"HIGH\", \"baseScore\": 6.4, \"baseSeverity\": \"MEDIUM\", \"vectorString\": \"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:H/SI:H/SA:H\", \"version\": \"4.0\"}}], \"references\": [{\"name\": \"https://github.com/go-vikunja/vikunja/security/advisories/GHSA-6q44-85gc-cjvf\", \"tags\": [\"x_refsource_CONFIRM\"], \"url\": \"https://github.com/go-vikunja/vikunja/security/advisories/GHSA-6q44-85gc-cjvf\"}, {\"name\": \"https://vikunja.io/changelog/vikunja-v2.2.0-was-released\", \"tags\": [\"x_refsource_MISC\"], \"url\": \"https://vikunja.io/changelog/vikunja-v2.2.0-was-released\"}], \"affected\": [{\"vendor\": \"go-vikunja\", \"product\": \"vikunja\", \"versions\": [{\"version\": \"\u003e= 0.21.0, \u003c 2.2.0\", \"status\": \"affected\"}]}], \"providerMetadata\": {\"orgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"shortName\": \"GitHub_M\", \"dateUpdated\": \"2026-03-24T15:07:41.460Z\"}, \"descriptions\": [{\"lang\": \"en\", \"value\": \"Vikunja is an open-source self-hosted task management platform. Starting in version 0.21.0 and prior to version 2.2.0, the Vikunja Desktop Electron wrapper passes URLs from `window.open()` calls directly to `shell.openExternal()` without any validation or protocol allowlisting. An attacker who can place a link with `target=\\\"_blank\\\"` (or that otherwise triggers `window.open`) in user-generated content can cause the victim\u0027s operating system to open arbitrary URI schemes, invoking local applications, opening local files, or triggering custom protocol handlers. Version 2.2.0 patches the issue.\"}], \"source\": {\"advisory\": \"GHSA-6q44-85gc-cjvf\", \"discovery\": \"UNKNOWN\"}}, \"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-33335\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"poc\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-03-25T13:41:45.712476Z\"}}}], \"references\": [{\"url\": \"https://github.com/go-vikunja/vikunja/security/advisories/GHSA-6q44-85gc-cjvf\", \"tags\": [\"exploit\"]}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-03-25T13:41:40.308Z\"}}]}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-33335\", \"assignerOrgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"state\": \"PUBLISHED\", \"assignerShortName\": \"GitHub_M\", \"dateReserved\": \"2026-03-18T22:15:11.812Z\", \"datePublished\": \"2026-03-24T15:07:41.460Z\", \"dateUpdated\": \"2026-03-25T13:41:50.096Z\"}",
      "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.