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

CVE-2026-91968 (GCVE-0-2026-91968)

Vulnerability from cvelistv5 – Published: 2026-09-15 15:18 – Updated: 2026-09-15 15:56
VLAI
Title
vikunja before 2.6.0 Denial of Service via unbounded filter recursion
Summary
vikunja versions before 2.6.0 contain a resource exhaustion vulnerability in the task-filter endpoint that accepts deeply nested filter expressions without recursion depth limits. Authenticated attackers can supply thousands of nested parentheses in the filter query parameter to exhaust memory and terminate the API process.
Severity
6.5 (Medium)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
7.1 (High)
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
SSVC
Exploitation: poc Automatable: no Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-15 15:55 UTC
CWE
Assigner
References
Impacted products
Vendor Product Version CPE status
go-vikunja vikunja Affected: 2.5.0 , < 2.6.0 (semver)
Unaffected: 2.6.0 (semver)
    cpe:2.3:a:vikunja:vikunja:*:*:*:*:*:*:*:*
Create a notification for this product.
Date Public
2026-08-31 00:00
Credits
Zyy0530 Str1ckl4nd 7thParkk
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-91968",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-09-15T15:55:42.634396Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-09-15T15:56:07.929Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "exploit"
            ],
            "url": "https://github.com/go-vikunja/vikunja/security/advisories/GHSA-xxc3-xpmc-vmvr"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "packageURL": "pkg:golang/code.vikunja.io/api",
          "product": "vikunja",
          "vendor": "go-vikunja",
          "versions": [
            {
              "lessThan": "2.6.0",
              "status": "affected",
              "version": "2.5.0",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "2.6.0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:a:vikunja:vikunja:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "2.6.0",
                  "versionStartIncluding": "2.5.0",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "reporter",
          "value": "Zyy0530"
        },
        {
          "lang": "en",
          "type": "reporter",
          "value": "Str1ckl4nd"
        },
        {
          "lang": "en",
          "type": "reporter",
          "value": "7thParkk"
        }
      ],
      "datePublic": "2026-08-31T00:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "value": "vikunja versions before 2.6.0 contain a resource exhaustion vulnerability in the task-filter endpoint that accepts deeply nested filter expressions without recursion depth limits. Authenticated attackers can supply thousands of nested parentheses in the filter query parameter to exhaust memory and terminate the API process."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 6.5,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
          },
          "format": "CVSS"
        },
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 7.1,
            "baseSeverity": "HIGH",
            "privilegesRequired": "LOW",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "NONE",
            "vulnIntegrityImpact": "NONE"
          },
          "format": "CVSS"
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-674",
              "description": "Uncontrolled Recursion",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-15T15:18:20.097Z",
        "orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
        "shortName": "VulnCheck"
      },
      "references": [
        {
          "name": "GitHub Security Advisory (GHSA-xxc3-xpmc-vmvr)",
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://github.com/go-vikunja/vikunja/security/advisories/GHSA-xxc3-xpmc-vmvr"
        },
        {
          "name": "VulnCheck Advisory: vikunja before 2.6.0 Denial of Service via unbounded filter recursion",
          "tags": [
            "third-party-advisory"
          ],
          "url": "https://www.vulncheck.com/advisories/vikunja-before-2.6.0-denial-of-service-via-unbounded-filter-recursion"
        }
      ],
      "title": "vikunja before 2.6.0 Denial of Service via unbounded filter recursion",
      "x_generator": {
        "engine": "vulncheck-endgame"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
    "assignerShortName": "VulnCheck",
    "cveId": "CVE-2026-91968",
    "datePublished": "2026-09-15T15:18:20.097Z",
    "dateReserved": "2026-09-15T11:08:44.670Z",
    "dateUpdated": "2026-09-15T15:56:07.929Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-91968",
      "date": "2026-09-16",
      "epss": "0.00368",
      "percentile": "0.30386"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-91968\",\"sourceIdentifier\":\"disclosure@vulncheck.com\",\"published\":\"2026-09-15T16:17:53.093\",\"lastModified\":\"2026-09-15T16:17:53.093\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"vikunja versions before 2.6.0 contain a resource exhaustion vulnerability in the task-filter endpoint that accepts deeply nested filter expressions without recursion depth limits. Authenticated attackers can supply thousands of nested parentheses in the filter query parameter to exhaust memory and terminate the API process.\"}],\"affected\":[{\"source\":\"disclosure@vulncheck.com\",\"affectedData\":[{\"vendor\":\"go-vikunja\",\"product\":\"vikunja\",\"defaultStatus\":\"unaffected\",\"packageURL\":\"pkg:golang/code.vikunja.io/api\",\"versions\":[{\"version\":\"2.5.0\",\"lessThan\":\"2.6.0\",\"versionType\":\"semver\",\"status\":\"affected\"},{\"version\":\"2.6.0\",\"versionType\":\"semver\",\"status\":\"unaffected\"}]}]}],\"metrics\":{\"cvssMetricV40\":[{\"source\":\"disclosure@vulncheck.com\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"4.0\",\"vectorString\":\"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/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\",\"baseScore\":7.1,\"baseSeverity\":\"HIGH\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"attackRequirements\":\"NONE\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"vulnConfidentialityImpact\":\"NONE\",\"vulnIntegrityImpact\":\"NONE\",\"vulnAvailabilityImpact\":\"HIGH\",\"subConfidentialityImpact\":\"NONE\",\"subIntegrityImpact\":\"NONE\",\"subAvailabilityImpact\":\"NONE\",\"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\":\"disclosure@vulncheck.com\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H\",\"baseScore\":6.5,\"baseSeverity\":\"MEDIUM\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":2.8,\"impactScore\":3.6}],\"ssvcV203\":[{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"ssvcData\":{\"timestamp\":\"2026-09-15T15:55:42.634396Z\",\"id\":\"CVE-2026-91968\",\"options\":[{\"exploitation\":\"poc\"},{\"automatable\":\"no\"},{\"technicalImpact\":\"partial\"}],\"role\":\"CISA Coordinator\",\"version\":\"2.0.3\"}}]},\"weaknesses\":[{\"source\":\"disclosure@vulncheck.com\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-674\"}]}],\"references\":[{\"url\":\"https://github.com/go-vikunja/vikunja/security/advisories/GHSA-xxc3-xpmc-vmvr\",\"source\":\"disclosure@vulncheck.com\"},{\"url\":\"https://www.vulncheck.com/advisories/vikunja-before-2.6.0-denial-of-service-via-unbounded-filter-recursion\",\"source\":\"disclosure@vulncheck.com\"},{\"url\":\"https://github.com/go-vikunja/vikunja/security/advisories/GHSA-xxc3-xpmc-vmvr\",\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\"}]}}",
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-91968\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"poc\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-09-15T15:55:42.634396Z\"}}}], \"references\": [{\"url\": \"https://github.com/go-vikunja/vikunja/security/advisories/GHSA-xxc3-xpmc-vmvr\", \"tags\": [\"exploit\"]}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-09-15T15:55:54.060Z\"}}], \"cna\": {\"title\": \"vikunja before 2.6.0 Denial of Service via unbounded filter recursion\", \"credits\": [{\"lang\": \"en\", \"type\": \"reporter\", \"value\": \"Zyy0530\"}, {\"lang\": \"en\", \"type\": \"reporter\", \"value\": \"Str1ckl4nd\"}, {\"lang\": \"en\", \"type\": \"reporter\", \"value\": \"7thParkk\"}], \"metrics\": [{\"format\": \"CVSS\", \"cvssV3_1\": {\"scope\": \"UNCHANGED\", \"version\": \"3.1\", \"baseScore\": 6.5, \"attackVector\": \"NETWORK\", \"baseSeverity\": \"MEDIUM\", \"vectorString\": \"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H\", \"integrityImpact\": \"NONE\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"availabilityImpact\": \"HIGH\", \"privilegesRequired\": \"LOW\", \"confidentialityImpact\": \"NONE\"}}, {\"format\": \"CVSS\", \"cvssV4_0\": {\"version\": \"4.0\", \"baseScore\": 7.1, \"attackVector\": \"NETWORK\", \"baseSeverity\": \"HIGH\", \"vectorString\": \"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"attackRequirements\": \"NONE\", \"privilegesRequired\": \"LOW\", \"subIntegrityImpact\": \"NONE\", \"vulnIntegrityImpact\": \"NONE\", \"subAvailabilityImpact\": \"NONE\", \"vulnAvailabilityImpact\": \"HIGH\", \"subConfidentialityImpact\": \"NONE\", \"vulnConfidentialityImpact\": \"NONE\"}}], \"affected\": [{\"vendor\": \"go-vikunja\", \"product\": \"vikunja\", \"versions\": [{\"status\": \"affected\", \"version\": \"2.5.0\", \"lessThan\": \"2.6.0\", \"versionType\": \"semver\"}, {\"status\": \"unaffected\", \"version\": \"2.6.0\", \"versionType\": \"semver\"}], \"packageURL\": \"pkg:golang/code.vikunja.io/api\", \"defaultStatus\": \"unaffected\"}], \"datePublic\": \"2026-08-31T00:00:00.000Z\", \"references\": [{\"url\": \"https://github.com/go-vikunja/vikunja/security/advisories/GHSA-xxc3-xpmc-vmvr\", \"name\": \"GitHub Security Advisory (GHSA-xxc3-xpmc-vmvr)\", \"tags\": [\"vendor-advisory\"]}, {\"url\": \"https://www.vulncheck.com/advisories/vikunja-before-2.6.0-denial-of-service-via-unbounded-filter-recursion\", \"name\": \"VulnCheck Advisory: vikunja before 2.6.0 Denial of Service via unbounded filter recursion\", \"tags\": [\"third-party-advisory\"]}], \"x_generator\": {\"engine\": \"vulncheck-endgame\"}, \"descriptions\": [{\"lang\": \"en\", \"value\": \"vikunja versions before 2.6.0 contain a resource exhaustion vulnerability in the task-filter endpoint that accepts deeply nested filter expressions without recursion depth limits. Authenticated attackers can supply thousands of nested parentheses in the filter query parameter to exhaust memory and terminate the API process.\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-674\", \"description\": \"Uncontrolled Recursion\"}]}], \"cpeApplicability\": [{\"nodes\": [{\"negate\": false, \"cpeMatch\": [{\"criteria\": \"cpe:2.3:a:vikunja:vikunja:*:*:*:*:*:*:*:*\", \"vulnerable\": true, \"versionEndExcluding\": \"2.6.0\", \"versionStartIncluding\": \"2.5.0\"}], \"operator\": \"OR\"}]}], \"providerMetadata\": {\"orgId\": \"83251b91-4cc7-4094-a5c7-464a1b83ea10\", \"shortName\": \"VulnCheck\", \"dateUpdated\": \"2026-09-15T15:18:20.097Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-91968\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-09-15T15:56:07.929Z\", \"dateReserved\": \"2026-09-15T11:08:44.670Z\", \"assignerOrgId\": \"83251b91-4cc7-4094-a5c7-464a1b83ea10\", \"datePublished\": \"2026-09-15T15:18:20.097Z\", \"assignerShortName\": \"VulnCheck\"}",
      "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.