Vulnerability-Lookup

CVE-2026-45820 (GCVE-0-2026-45820)

Vulnerability from cvelistv5 – Published: 2026-07-22 06:57 – Updated: 2026-07-22 12:53

Summary

fflate through 0.8.2 is vulnerable to denial of service via an infinite loop in unzipSync(). A crafted ZIP archive with a central directory entry declaring compressed_size=0xFFFFFFFF (ZIP64 sentinel) but missing the required ZIP64 extra field tag 0x0001 causes z64e() to loop indefinitely due to out-of-bounds reads returning undefined, which coerces to 0, keeping the loop condition permanently true.

Severity

6.6 (Medium)


                        
                          CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/S:N/AU:Y/R:U/V:D/RE:M/U:Amber

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-07-22 12:53 UTC

CWE

CWE-835 - Loop with Unreachable Exit Condition ('Infinite Loop')
CWE-400 - Uncontrolled Resource Consumption

Assigner

seal mitre root

References

2 references

URL	Tags
https://github.com/101arrowz/fflate/blob/f7873560…
https://www.npmjs.com/package/fflate

Impacted products

1 product

Vendor	Product	Version	CPE status
101arrowz	fflate	Affected: 0.4.5 , ≤ 0.4.8 (semver) Affected: 0.5.0 , ≤ 0.5.3 (semver) Affected: 0.6.0 , ≤ 0.6.10 (semver) Affected: 0.7.0 , ≤ 0.7.4 (semver) Affected: 0.8.0 , ≤ 0.8.2 (semver)	guessed

Credits

Seal Security

Show details on NVD website

JSON

To clipboard

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FKIE_CVE-2026-45820

Vulnerability from fkie_nvd - Published: 2026-07-22 08:16 - Updated: 2026-08-19 19:06

Severity

7.5 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Summary

References

	URL	Tags
	22e2d327-25fe-45d7-9f0c-dcd23b7108df	https://github.com/101arrowz/fflate/blob/f7873560ad229c22c4b23b06c6a3806ffde77569/src/index.ts#L2714	Patch
	22e2d327-25fe-45d7-9f0c-dcd23b7108df	https://www.npmjs.com/package/fflate	Product

Impacted products

	Vendor	Product	Version
	101arrowz	fflate	*

JSON

To clipboard

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      "affectedData": [
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          "defaultStatus": "unaffected",
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            "macOS",
            "Windows"
          ],
          "product": "fflate",
          "vendor": "101arrowz",
          "versions": [
            {
              "lessThanOrEqual": "0.4.8",
              "status": "affected",
              "version": "0.4.5",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "0.5.3",
              "status": "affected",
              "version": "0.5.0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "0.6.10",
              "status": "affected",
              "version": "0.6.0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "0.7.4",
              "status": "affected",
              "version": "0.7.0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "0.8.2",
              "status": "affected",
              "version": "0.8.0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "source": "22e2d327-25fe-45d7-9f0c-dcd23b7108df"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:101arrowz:fflate:*:*:*:*:*:node.js:*:*",
              "matchCriteriaId": "333D4003-1B80-4B59-A091-E01AE7A6A237",
              "versionEndIncluding": "0.8.2",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "fflate through 0.8.2 is vulnerable to denial of service via an infinite loop in unzipSync(). A crafted ZIP archive with a central directory entry declaring compressed_size=0xFFFFFFFF (ZIP64 sentinel) but missing the required ZIP64 extra field tag 0x0001 causes z64e() to loop indefinitely due to out-of-bounds reads returning undefined, which coerces to 0, keeping the loop condition permanently true."
    }
  ],
  "id": "CVE-2026-45820",
  "lastModified": "2026-08-19T19:06:39.440",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.6,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ],
    "cvssMetricV40": [
      {
        "cvssData": {
          "Automatable": "YES",
          "Recovery": "USER",
          "Safety": "NEGLIGIBLE",
          "attackComplexity": "LOW",
          "attackRequirements": "NONE",
          "attackVector": "NETWORK",
          "availabilityRequirement": "NOT_DEFINED",
          "baseScore": 6.6,
          "baseSeverity": "MEDIUM",
          "confidentialityRequirement": "NOT_DEFINED",
          "exploitMaturity": "UNREPORTED",
          "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": "NONE",
          "providerUrgency": "AMBER",
          "subAvailabilityImpact": "NONE",
          "subConfidentialityImpact": "NONE",
          "subIntegrityImpact": "NONE",
          "userInteraction": "NONE",
          "valueDensity": "DIFFUSE",
          "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/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:N/AU:Y/R:U/V:D/RE:M/U:Amber",
          "version": "4.0",
          "vulnAvailabilityImpact": "HIGH",
          "vulnConfidentialityImpact": "NONE",
          "vulnIntegrityImpact": "NONE",
          "vulnerabilityResponseEffort": "MODERATE"
        },
        "source": "22e2d327-25fe-45d7-9f0c-dcd23b7108df",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-45820",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-07-22T12:53:26.309456Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-07-22T08:16:23.280",
  "references": [
    {
      "source": "22e2d327-25fe-45d7-9f0c-dcd23b7108df",
      "tags": [
        "Patch"
      ],
      "url": "https://github.com/101arrowz/fflate/blob/f7873560ad229c22c4b23b06c6a3806ffde77569/src/index.ts#L2714"
    },
    {
      "source": "22e2d327-25fe-45d7-9f0c-dcd23b7108df",
      "tags": [
        "Product"
      ],
      "url": "https://www.npmjs.com/package/fflate"
    }
  ],
  "sourceIdentifier": "22e2d327-25fe-45d7-9f0c-dcd23b7108df",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-400"
        },
        {
          "lang": "en",
          "value": "CWE-835"
        }
      ],
      "source": "22e2d327-25fe-45d7-9f0c-dcd23b7108df",
      "type": "Secondary"
    }
  ]
}

GHSA-PX8P-9VWX-VF98

Vulnerability from github – Published: 2026-07-22 09:32 – Updated: 2026-09-03 14:58

Summary

fflate unzipSync can enter an infinite loop when parsing malformed ZIP64 archives

Details

Severity

7.5 (High)


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

6.6 (Medium)


                  
                    CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/S:N/AU:Y/R:U/V:D/RE:M/U:Amber

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "fflate"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0.4.5"
            },
            {
              "fixed": "0.4.9"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "fflate"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0.5.0"
            },
            {
              "fixed": "0.5.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "fflate"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0.6.0"
            },
            {
              "fixed": "0.6.11"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "fflate"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0.7.0"
            },
            {
              "fixed": "0.7.5"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "fflate"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0.8.0"
            },
            {
              "fixed": "0.8.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-45820"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-400"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-09-03T14:58:12Z",
    "nvd_published_at": "2026-07-22T08:16:23Z",
    "severity": "MODERATE"
  },
  "details": "fflate through 0.8.2 is vulnerable to denial of service via an infinite loop in unzipSync(). A crafted ZIP archive with a central directory entry declaring compressed_size=0xFFFFFFFF (ZIP64 sentinel) but missing the required ZIP64 extra field tag 0x0001 causes z64e() to loop indefinitely due to out-of-bounds reads returning undefined, which coerces to 0, keeping the loop condition permanently true.",
  "id": "GHSA-px8p-9vwx-vf98",
  "modified": "2026-09-03T14:58:12Z",
  "published": "2026-07-22T09:32:13Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-45820"
    },
    {
      "type": "WEB",
      "url": "https://github.com/101arrowz/fflate/commit/e6d5e6e1076892f72770ac732d83c81da9f3316e"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/101arrowz/fflate"
    },
    {
      "type": "WEB",
      "url": "https://github.com/101arrowz/fflate/blob/f7873560ad229c22c4b23b06c6a3806ffde77569/src/index.ts#L2714"
    },
    {
      "type": "WEB",
      "url": "https://github.com/101arrowz/fflate/releases/tag/v0.8.3"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/S:N/AU:Y/R:U/V:D/RE:M/U:Amber",
      "type": "CVSS_V4"
    }
  ],
  "summary": "fflate unzipSync can enter an infinite loop when parsing malformed ZIP64 archives"
}

RHSA-2026:68690

Vulnerability from csaf_redhat - Published: 2026-09-17 15:27 - Updated: 2026-09-21 17:07

Summary

Red Hat Security Advisory: Kiali 2.22.10 for Red Hat OpenShift Service Mesh 3.3

Severity

Important

Scope

6 vulnerabilities in this advisory, including CVE-2026-45820.

CVE-2026-45820

A flaw was found in fflate. A remote attacker could exploit this vulnerability by providing a specially crafted ZIP archive. This archive, when processed, can lead to an infinite loop during decompression, causing a Denial of Service (DoS) condition. This occurs because a malformed central directory entry in the ZIP archive causes out-of-bounds reads, which keeps a processing loop permanently active.

7.5 (High)


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

Fixed: 8 products

https://access.redhat.com/errata/RHSA-2026:68690

Open the full advisory

RHSA-2026:68695

Vulnerability from csaf_redhat - Published: 2026-09-17 15:45 - Updated: 2026-09-21 17:07

Summary

Red Hat Security Advisory: Kiali 2.27.4 for Red Hat OpenShift Service Mesh 3.4

Severity

Important

Scope

6 vulnerabilities in this advisory, including CVE-2026-45820.

CVE-2026-45820

7.5 (High)


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

Fixed: 8 products Known not affected: 5 products

https://access.redhat.com/errata/RHSA-2026:68695

Open the full advisory

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.

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.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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.

Action not permitted

CVE-2026-45820 (GCVE-0-2026-45820)

FKIE_CVE-2026-45820

GHSA-PX8P-9VWX-VF98

RHSA-2026:68690

RHSA-2026:68695

Tags

Sightings

Nomenclature

Related by attack behaviour