Vulnerability-Lookup

GHSA-5R36-V86R-VM5X

Vulnerability from github – Published: 2026-09-09 12:32 – Updated: 2026-09-09 12:32

Details

KeePass versions 2.35 through 2.61.1 fail to validate KDBX header field sizes before memory allocation in the ReadHeaderField function. Attackers can craft a malicious KDBX file declaring excessive header field lengths to trigger allocation of gigabytes of memory, causing the application to consume resources and terminate.

Severity

3.3 (Low)


                  
                    CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L

4.6 (Medium)


                  
                    CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

Show details on source website

JSON

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{
  "affected": [],
  "aliases": [
    "CVE-2026-86776"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-789"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-09T10:22:33Z",
    "severity": "MODERATE"
  },
  "details": "KeePass versions 2.35 through 2.61.1 fail to validate KDBX header field sizes before memory allocation in the ReadHeaderField function. Attackers can craft a malicious KDBX file declaring excessive header field lengths to trigger allocation of gigabytes of memory, causing the application to consume resources and terminate.",
  "id": "GHSA-5r36-v86r-vm5x",
  "modified": "2026-09-09T12:32:11Z",
  "published": "2026-09-09T12:32:11Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-86776"
    },
    {
      "type": "WEB",
      "url": "https://github.com/KSecur1ty/KDBX-Header-Size-Mirage-POC"
    },
    {
      "type": "WEB",
      "url": "https://keepass.info"
    },
    {
      "type": "WEB",
      "url": "https://keepass.info/download.html"
    },
    {
      "type": "WEB",
      "url": "https://www.vulncheck.com/advisories/keepass-2.35-through-2.61.1-memory-exhaustion-via-kdbx-header-field-size"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/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",
      "type": "CVSS_V4"
    }
  ]
}

CVE-2026-86776 (GCVE-0-2026-86776)

Vulnerability from cvelistv5 – Published: 2026-09-09 10:07 – Updated: 2026-09-10 14:58

Title

KeePass 2.35 through 2.61.1 Memory Exhaustion via KDBX Header Field Size

Summary

Severity

3.3 (Low)


                        
                          CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L

4.6 (Medium)


                        
                          CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

SSVC

Exploitation: poc Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-09-10 13:48 UTC

CWE

CWE-789 - Memory Allocation with Excessive Size Value

Assigner

VulnCheck mitre root Scorecard

References

4 references

URL	Tags
https://github.com/KSecur1ty/KDBX-Header-Size-Mir…	exploittechnical-description
https://keepass.info/	product
https://keepass.info/download.html	product
https://www.vulncheck.com/advisories/keepass-2.35…	third-party-advisory

Impacted products

1 product

Vendor	Product	Version
KeePass	KeePass	Affected: 2.35 , ≤ 2.61.1 (custom) cpe:2.3:a:keepass:keepass::::::::

Date Public

2026-08-13 00:00

Credits

KSecur1ty

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-86776",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-09-10T13:48:59.785045Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-09-10T14:58:52.747Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "collectionURL": "https://keepass.info/",
          "defaultStatus": "unaffected",
          "product": "KeePass",
          "vendor": "KeePass",
          "versions": [
            {
              "lessThanOrEqual": "2.61.1",
              "status": "affected",
              "version": "2.35",
              "versionType": "custom"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:a:keepass:keepass:*:*:*:*:*:*:*:*",
                  "versionEndIncluding": "2.61.1",
                  "versionStartIncluding": "2.35",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "KSecur1ty"
        }
      ],
      "datePublic": "2026-08-13T00:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "value": "KeePass versions 2.35 through 2.61.1 fail to validate KDBX header field sizes before memory allocation in the ReadHeaderField function. Attackers can craft a malicious KDBX file declaring excessive header field lengths to trigger allocation of gigabytes of memory, causing the application to consume resources and terminate."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "LOCAL",
            "availabilityImpact": "LOW",
            "baseScore": 3.3,
            "baseSeverity": "LOW",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L",
            "version": "3.1"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        },
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "LOCAL",
            "baseScore": 4.6,
            "baseSeverity": "MEDIUM",
            "privilegesRequired": "NONE",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "ACTIVE",
            "vectorString": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "LOW",
            "vulnConfidentialityImpact": "NONE",
            "vulnIntegrityImpact": "NONE"
          },
          "format": "CVSS"
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-789",
              "description": "Memory Allocation with Excessive Size Value",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-09T10:07:26.502Z",
        "orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
        "shortName": "VulnCheck"
      },
      "references": [
        {
          "name": "Reporter write-up and proof of concept",
          "tags": [
            "exploit",
            "technical-description"
          ],
          "url": "https://github.com/KSecur1ty/KDBX-Header-Size-Mirage-POC"
        },
        {
          "tags": [
            "product"
          ],
          "url": "https://keepass.info/"
        },
        {
          "name": "KeePass 2.61.1 downloads (including source)",
          "tags": [
            "product"
          ],
          "url": "https://keepass.info/download.html"
        },
        {
          "name": "VulnCheck Advisory: KeePass 2.35 through 2.61.1 Memory Exhaustion via KDBX Header Field Size",
          "tags": [
            "third-party-advisory"
          ],
          "url": "https://www.vulncheck.com/advisories/keepass-2.35-through-2.61.1-memory-exhaustion-via-kdbx-header-field-size"
        }
      ],
      "source": {
        "discovery": "EXTERNAL"
      },
      "title": "KeePass 2.35 through 2.61.1 Memory Exhaustion via KDBX Header Field Size",
      "x_generator": {
        "engine": "vulncheck-endgame"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
    "assignerShortName": "VulnCheck",
    "cveId": "CVE-2026-86776",
    "datePublished": "2026-09-09T10:07:26.502Z",
    "dateReserved": "2026-09-08T11:35:02.617Z",
    "dateUpdated": "2026-09-10T14:58:52.747Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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GHSA-5R36-V86R-VM5X

CVE-2026-86776 (GCVE-0-2026-86776)

Tags

Sightings

Nomenclature

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