CVE-2025-4918 (GCVE-0-2025-4918)

Vulnerability from cvelistv5 – Published: 2025-05-17 21:07 – Updated: 2026-04-13 14:25
VLAI
Title
Out-of-bounds access when resolving Promise objects
Summary
An attacker was able to perform an out-of-bounds read or write on a JavaScript `Promise` object. This vulnerability was fixed in Firefox 138.0.4, Firefox ESR 128.10.1, Firefox ESR 115.23.1, Thunderbird 128.10.2, and Thunderbird 138.0.2.
Severity
9.8 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
SSVC
Exploitation: none Automatable: no Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2025-05-20 03:55 UTC
CWE
Assigner
mozilla CNA under the mitre root
CNA scorecard E 38/100 over 509 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
Mozilla Firefox Unaffected: 115.23.1 , ≤ 115.* (rpm)
Unaffected: 128.10.1 , ≤ 128.* (rpm)
Unaffected: 138.0.4 , ≤ * (rpm)
guessed Create a notification for this product.
Mozilla Thunderbird Unaffected: 128.10.2 , ≤ 128.* (rpm)
Unaffected: 138.0.2 , ≤ * (rpm)
guessed Create a notification for this product.
Credits
Edouard Bochin and Tao Yan from Palo Alto Networks working with Trend Micro's Zero Day Initiative
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "NETWORK",
              "availabilityImpact": "HIGH",
              "baseScore": 9.8,
              "baseSeverity": "CRITICAL",
              "confidentialityImpact": "HIGH",
              "integrityImpact": "HIGH",
              "privilegesRequired": "NONE",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2025-4918",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2025-05-20T03:55:17.219008Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "problemTypes": [
          {
            "descriptions": [
              {
                "cweId": "CWE-125",
                "description": "CWE-125 Out-of-bounds Read",
                "lang": "en",
                "type": "CWE"
              }
            ]
          },
          {
            "descriptions": [
              {
                "cweId": "CWE-787",
                "description": "CWE-787 Out-of-bounds Write",
                "lang": "en",
                "type": "CWE"
              }
            ]
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-02-26T18:28:06.529Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      },
      {
        "providerMetadata": {
          "dateUpdated": "2025-11-03T20:05:17.591Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "url": "https://www.vicarius.io/vsociety/posts/cve-2025-4918-detect-firefox-out-of-bounds-write"
          },
          {
            "url": "https://www.vicarius.io/vsociety/posts/cve-2025-4918-mitigate-firefox-out-of-bounds-write"
          },
          {
            "url": "https://lists.debian.org/debian-lts-announce/2025/05/msg00046.html"
          },
          {
            "url": "https://lists.debian.org/debian-lts-announce/2025/05/msg00024.html"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "Firefox",
          "vendor": "Mozilla",
          "versions": [
            {
              "lessThanOrEqual": "115.*",
              "status": "unaffected",
              "version": "115.23.1",
              "versionType": "rpm"
            },
            {
              "lessThanOrEqual": "128.*",
              "status": "unaffected",
              "version": "128.10.1",
              "versionType": "rpm"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "138.0.4",
              "versionType": "rpm"
            }
          ]
        },
        {
          "product": "Thunderbird",
          "vendor": "Mozilla",
          "versions": [
            {
              "lessThanOrEqual": "128.*",
              "status": "unaffected",
              "version": "128.10.2",
              "versionType": "rpm"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "138.0.2",
              "versionType": "rpm"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "value": "Edouard Bochin and Tao Yan from Palo Alto Networks working with Trend Micro\u0027s Zero Day Initiative"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "An attacker was able to perform an out-of-bounds read or write on a JavaScript `Promise` object. This vulnerability was fixed in Firefox 138.0.4, Firefox ESR 128.10.1, Firefox ESR 115.23.1, Thunderbird 128.10.2, and Thunderbird 138.0.2."
            }
          ],
          "value": "An attacker was able to perform an out-of-bounds read or write on a JavaScript `Promise` object. This vulnerability was fixed in Firefox 138.0.4, Firefox ESR 128.10.1, Firefox ESR 115.23.1, Thunderbird 128.10.2, and Thunderbird 138.0.2."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-04-13T14:25:54.968Z",
        "orgId": "f16b083a-5664-49f3-a51e-8d479e5ed7fe",
        "shortName": "mozilla"
      },
      "references": [
        {
          "url": "https://bugzilla.mozilla.org/show_bug.cgi?id=1966612"
        },
        {
          "url": "https://www.mozilla.org/security/advisories/mfsa2025-36/"
        },
        {
          "url": "https://www.mozilla.org/security/advisories/mfsa2025-37/"
        },
        {
          "url": "https://www.mozilla.org/security/advisories/mfsa2025-38/"
        },
        {
          "url": "https://www.mozilla.org/security/advisories/mfsa2025-40/"
        },
        {
          "url": "https://www.mozilla.org/security/advisories/mfsa2025-41/"
        }
      ],
      "title": "Out-of-bounds access when resolving Promise objects"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "f16b083a-5664-49f3-a51e-8d479e5ed7fe",
    "assignerShortName": "mozilla",
    "cveId": "CVE-2025-4918",
    "datePublished": "2025-05-17T21:07:26.745Z",
    "dateReserved": "2025-05-17T19:40:51.300Z",
    "dateUpdated": "2026-04-13T14:25:54.968Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2025-4918",
      "date": "2026-10-26",
      "epss": "0.09515",
      "percentile": "0.95415"
    },
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "product": "Firefox",
                "vendor": "Mozilla",
                "versions": [
                  {
                    "lessThanOrEqual": "115.*",
                    "status": "unaffected",
                    "version": "115.23.1",
                    "versionType": "rpm"
                  },
                  {
                    "lessThanOrEqual": "128.*",
                    "status": "unaffected",
                    "version": "128.10.1",
                    "versionType": "rpm"
                  },
                  {
                    "lessThanOrEqual": "*",
                    "status": "unaffected",
                    "version": "138.0.4",
                    "versionType": "rpm"
                  }
                ]
              },
              {
                "product": "Thunderbird",
                "vendor": "Mozilla",
                "versions": [
                  {
                    "lessThanOrEqual": "128.*",
                    "status": "unaffected",
                    "version": "128.10.2",
                    "versionType": "rpm"
                  },
                  {
                    "lessThanOrEqual": "*",
                    "status": "unaffected",
                    "version": "138.0.2",
                    "versionType": "rpm"
                  }
                ]
              }
            ],
            "source": "security@mozilla.org"
          }
        ],
        "configurations": [
          {
            "nodes": [
              {
                "cpeMatch": [
                  {
                    "criteria": "cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*",
                    "matchCriteriaId": "BD156D89-BD24-483A-A355-1B45A0A2E66F",
                    "versionEndExcluding": "115.23.1",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*",
                    "matchCriteriaId": "83AE9635-80D1-49DD-B7A5-8E4E235B1C87",
                    "versionEndExcluding": "138.0.4",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*",
                    "matchCriteriaId": "7F2F0DE1-8619-4C18-83B0-46E543AE8E9E",
                    "versionEndExcluding": "128.10.1",
                    "versionStartIncluding": "116.0",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*",
                    "matchCriteriaId": "08FDB838-27AF-43C3-AC02-27C34ED5481A",
                    "versionEndExcluding": "128.10.2",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:a:mozilla:thunderbird:*:*:*:*:-:*:*:*",
                    "matchCriteriaId": "F76ABBB9-7E44-45A0-BEE9-81CD9C0A33ED",
                    "versionEndExcluding": "138.0.2",
                    "versionStartIncluding": "138.0",
                    "vulnerable": true
                  }
                ],
                "negate": false,
                "operator": "OR"
              }
            ]
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "An attacker was able to perform an out-of-bounds read or write on a JavaScript `Promise` object. This vulnerability was fixed in Firefox 138.0.4, Firefox ESR 128.10.1, Firefox ESR 115.23.1, Thunderbird 128.10.2, and Thunderbird 138.0.2."
          },
          {
            "lang": "es",
            "value": "Un atacante logr\u00f3 realizar una lectura o escritura fuera de los l\u00edmites en un objeto \u201cPromise\u201d de JavaScript. Esta vulnerabilidad afecta a Firefox (versi\u00f3n anterior a 138.0.4), Firefox ESR (versi\u00f3n anterior a 128.10.1) y Firefox ESR (versi\u00f3n anterior a 115.23.1)."
          }
        ],
        "id": "CVE-2025-4918",
        "lastModified": "2026-09-30T18:10:00.190",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "NETWORK",
                "availabilityImpact": "HIGH",
                "baseScore": 9.8,
                "baseSeverity": "CRITICAL",
                "confidentialityImpact": "HIGH",
                "integrityImpact": "HIGH",
                "privilegesRequired": "NONE",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
                "version": "3.1"
              },
              "exploitabilityScore": 3.9,
              "impactScore": 5.9,
              "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "type": "Secondary"
            }
          ],
          "ssvcV203": [
            {
              "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "ssvcData": {
                "id": "CVE-2025-4918",
                "options": [
                  {
                    "exploitation": "none"
                  },
                  {
                    "automatable": "no"
                  },
                  {
                    "technicalImpact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2025-05-20T03:55:17.219008Z",
                "version": "2.0.3"
              }
            }
          ]
        },
        "published": "2025-05-17T22:15:19.563",
        "references": [
          {
            "source": "security@mozilla.org",
            "tags": [
              "Permissions Required"
            ],
            "url": "https://bugzilla.mozilla.org/show_bug.cgi?id=1966612"
          },
          {
            "source": "security@mozilla.org",
            "tags": [
              "Vendor Advisory"
            ],
            "url": "https://www.mozilla.org/security/advisories/mfsa2025-36/"
          },
          {
            "source": "security@mozilla.org",
            "tags": [
              "Vendor Advisory"
            ],
            "url": "https://www.mozilla.org/security/advisories/mfsa2025-37/"
          },
          {
            "source": "security@mozilla.org",
            "tags": [
              "Vendor Advisory"
            ],
            "url": "https://www.mozilla.org/security/advisories/mfsa2025-38/"
          },
          {
            "source": "security@mozilla.org",
            "tags": [
              "Vendor Advisory"
            ],
            "url": "https://www.mozilla.org/security/advisories/mfsa2025-40/"
          },
          {
            "source": "security@mozilla.org",
            "tags": [
              "Vendor Advisory"
            ],
            "url": "https://www.mozilla.org/security/advisories/mfsa2025-41/"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "url": "https://lists.debian.org/debian-lts-announce/2025/05/msg00024.html"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "url": "https://lists.debian.org/debian-lts-announce/2025/05/msg00046.html"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Exploit",
              "Third Party Advisory"
            ],
            "url": "https://www.vicarius.io/vsociety/posts/cve-2025-4918-detect-firefox-out-of-bounds-write"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Exploit",
              "Third Party Advisory"
            ],
            "url": "https://www.vicarius.io/vsociety/posts/cve-2025-4918-mitigate-firefox-out-of-bounds-write"
          }
        ],
        "sourceIdentifier": "security@mozilla.org",
        "vulnStatus": "Modified",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-125"
              },
              {
                "lang": "en",
                "value": "CWE-787"
              }
            ],
            "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
            "type": "Secondary"
          }
        ]
      }
    },
    "redhat_vex": {
      "aggregate_severity": "Important",
      "current_release_date": "2026-06-28T07:03:54+00:00",
      "cve": "CVE-2025-4918",
      "id": "CVE-2025-4918",
      "initial_release_date": "2025-05-17T21:07:26.745000+00:00",
      "product_status:fixed": "253",
      "product_status:known_affected": "8",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "firefox: thunderbird: Out-of-bounds access when resolving Promise objects",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-4918.json",
      "version": "3"
    },
    "vulnrichment": {
      "containers": {
        "adp": [
          {
            "providerMetadata": {
              "dateUpdated": "2025-11-03T20:05:17.591Z",
              "orgId": "af854a3a-2127-422b-91ae-364da2661108",
              "shortName": "CVE"
            },
            "references": [
              {
                "url": "https://www.vicarius.io/vsociety/posts/cve-2025-4918-detect-firefox-out-of-bounds-write"
              },
              {
                "url": "https://www.vicarius.io/vsociety/posts/cve-2025-4918-mitigate-firefox-out-of-bounds-write"
              },
              {
                "url": "https://lists.debian.org/debian-lts-announce/2025/05/msg00046.html"
              },
              {
                "url": "https://lists.debian.org/debian-lts-announce/2025/05/msg00024.html"
              }
            ],
            "title": "CVE Program Container"
          },
          {
            "metrics": [
              {
                "cvssV3_1": {
                  "attackComplexity": "LOW",
                  "attackVector": "NETWORK",
                  "availabilityImpact": "HIGH",
                  "baseScore": 9.8,
                  "baseSeverity": "CRITICAL",
                  "confidentialityImpact": "HIGH",
                  "integrityImpact": "HIGH",
                  "privilegesRequired": "NONE",
                  "scope": "UNCHANGED",
                  "userInteraction": "NONE",
                  "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
                  "version": "3.1"
                }
              },
              {
                "other": {
                  "content": {
                    "id": "CVE-2025-4918",
                    "options": [
                      {
                        "Exploitation": "none"
                      },
                      {
                        "Automatable": "no"
                      },
                      {
                        "Technical Impact": "total"
                      }
                    ],
                    "role": "CISA Coordinator",
                    "timestamp": "2025-05-20T03:55:17.219008Z",
                    "version": "2.0.3"
                  },
                  "type": "ssvc"
                }
              }
            ],
            "problemTypes": [
              {
                "descriptions": [
                  {
                    "cweId": "CWE-125",
                    "description": "CWE-125 Out-of-bounds Read",
                    "lang": "en",
                    "type": "CWE"
                  }
                ]
              },
              {
                "descriptions": [
                  {
                    "cweId": "CWE-787",
                    "description": "CWE-787 Out-of-bounds Write",
                    "lang": "en",
                    "type": "CWE"
                  }
                ]
              }
            ],
            "providerMetadata": {
              "dateUpdated": "2025-05-19T20:09:59.882Z",
              "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "shortName": "CISA-ADP"
            },
            "title": "CISA ADP Vulnrichment"
          }
        ],
        "cna": {
          "affected": [
            {
              "product": "Firefox",
              "vendor": "Mozilla",
              "versions": [
                {
                  "lessThanOrEqual": "115.*",
                  "status": "unaffected",
                  "version": "115.23.1",
                  "versionType": "rpm"
                },
                {
                  "lessThanOrEqual": "128.*",
                  "status": "unaffected",
                  "version": "128.10.1",
                  "versionType": "rpm"
                },
                {
                  "lessThanOrEqual": "*",
                  "status": "unaffected",
                  "version": "138.0.4",
                  "versionType": "rpm"
                }
              ]
            },
            {
              "product": "Thunderbird",
              "vendor": "Mozilla",
              "versions": [
                {
                  "lessThanOrEqual": "128.*",
                  "status": "unaffected",
                  "version": "128.10.2",
                  "versionType": "rpm"
                },
                {
                  "lessThanOrEqual": "*",
                  "status": "unaffected",
                  "version": "138.0.2",
                  "versionType": "rpm"
                }
              ]
            }
          ],
          "credits": [
            {
              "lang": "en",
              "value": "Edouard Bochin and Tao Yan from Palo Alto Networks working with Trend Micro\u0027s Zero Day Initiative"
            }
          ],
          "descriptions": [
            {
              "lang": "en",
              "supportingMedia": [
                {
                  "base64": false,
                  "type": "text/html",
                  "value": "An attacker was able to perform an out-of-bounds read or write on a JavaScript `Promise` object. This vulnerability was fixed in Firefox 138.0.4, Firefox ESR 128.10.1, Firefox ESR 115.23.1, Thunderbird 128.10.2, and Thunderbird 138.0.2."
                }
              ],
              "value": "An attacker was able to perform an out-of-bounds read or write on a JavaScript `Promise` object. This vulnerability was fixed in Firefox 138.0.4, Firefox ESR 128.10.1, Firefox ESR 115.23.1, Thunderbird 128.10.2, and Thunderbird 138.0.2."
            }
          ],
          "providerMetadata": {
            "dateUpdated": "2026-04-13T14:25:54.968Z",
            "orgId": "f16b083a-5664-49f3-a51e-8d479e5ed7fe",
            "shortName": "mozilla"
          },
          "references": [
            {
              "url": "https://bugzilla.mozilla.org/show_bug.cgi?id=1966612"
            },
            {
              "url": "https://www.mozilla.org/security/advisories/mfsa2025-36/"
            },
            {
              "url": "https://www.mozilla.org/security/advisories/mfsa2025-37/"
            },
            {
              "url": "https://www.mozilla.org/security/advisories/mfsa2025-38/"
            },
            {
              "url": "https://www.mozilla.org/security/advisories/mfsa2025-40/"
            },
            {
              "url": "https://www.mozilla.org/security/advisories/mfsa2025-41/"
            }
          ],
          "title": "Out-of-bounds access when resolving Promise objects"
        }
      },
      "cveMetadata": {
        "assignerOrgId": "f16b083a-5664-49f3-a51e-8d479e5ed7fe",
        "assignerShortName": "mozilla",
        "cveId": "CVE-2025-4918",
        "datePublished": "2025-05-17T21:07:26.745Z",
        "dateReserved": "2025-05-17T19:40:51.300Z",
        "dateUpdated": "2026-04-13T14:25:54.968Z",
        "state": "PUBLISHED"
      },
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.

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.
Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

JSON

Loading timeline…




    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.