CVE-2025-4918

  1. OpenCVE
  2. Vulnerabilities (CVE)
  3. CVE-2025-4918
An attacker was able to perform an out-of-bounds read or write on a JavaScript `Promise` object. This vulnerability affects Firefox < 138.0.4, Firefox ESR < 128.10.1, Firefox ESR < 115.23.1, Thunderbird < 128.10.2, and Thunderbird < 138.0.2.

9.8 /10

CVSS v3 : CRITICAL

V3 Legend

Vector :

Exploitability : 3.9 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References
Link Resource
https://bugzilla.mozilla.org/show_bug.cgi?id=1966612 Permissions Required
https://www.mozilla.org/security/advisories/mfsa2025-36/ Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-37/ Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-38/ Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-40/ Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-41/ Vendor Advisory
https://www.vicarius.io/vsociety/posts/cve-2025-4918-detect-firefox-out-of-bounds-write Exploit Third Party Advisory
https://www.vicarius.io/vsociety/posts/cve-2025-4918-mitigate-firefox-out-of-bounds-write Exploit Third Party Advisory
Configurations

Configuration 1 (hide)

OR cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*
cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*
cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:-:*:*:*
History

22 Sep 2025, 18:15

Type Values Removed Values Added
CVSS v2 : unknown
v3 : 7.5 		v2 : unknown
v3 : 9.8
References () https://www.vicarius.io/vsociety/posts/cve-2025-4918-detect-firefox-out-of-bounds-write - Third Party Advisory, Exploit () https://www.vicarius.io/vsociety/posts/cve-2025-4918-detect-firefox-out-of-bounds-write - Exploit, Third Party Advisory
References () https://www.vicarius.io/vsociety/posts/cve-2025-4918-mitigate-firefox-out-of-bounds-write - Third Party Advisory, Exploit () https://www.vicarius.io/vsociety/posts/cve-2025-4918-mitigate-firefox-out-of-bounds-write - Exploit, Third Party Advisory
CWE CWE-787

28 May 2025, 14:05

Type Values Removed Values Added
First Time Mozilla
Mozilla thunderbird
Mozilla firefox
CPE cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:-:*:*:*
cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*
References () https://bugzilla.mozilla.org/show_bug.cgi?id=1966612 - () https://bugzilla.mozilla.org/show_bug.cgi?id=1966612 - Permissions Required
References () https://www.mozilla.org/security/advisories/mfsa2025-36/ - () https://www.mozilla.org/security/advisories/mfsa2025-36/ - Vendor Advisory
References () https://www.mozilla.org/security/advisories/mfsa2025-37/ - () https://www.mozilla.org/security/advisories/mfsa2025-37/ - Vendor Advisory
References () https://www.mozilla.org/security/advisories/mfsa2025-38/ - () https://www.mozilla.org/security/advisories/mfsa2025-38/ - Vendor Advisory
References () https://www.mozilla.org/security/advisories/mfsa2025-40/ - () https://www.mozilla.org/security/advisories/mfsa2025-40/ - Vendor Advisory
References () https://www.mozilla.org/security/advisories/mfsa2025-41/ - () https://www.mozilla.org/security/advisories/mfsa2025-41/ - Vendor Advisory
References () https://www.vicarius.io/vsociety/posts/cve-2025-4918-detect-firefox-out-of-bounds-write - () https://www.vicarius.io/vsociety/posts/cve-2025-4918-detect-firefox-out-of-bounds-write - Third Party Advisory, Exploit
References () https://www.vicarius.io/vsociety/posts/cve-2025-4918-mitigate-firefox-out-of-bounds-write - () https://www.vicarius.io/vsociety/posts/cve-2025-4918-mitigate-firefox-out-of-bounds-write - Third Party Advisory, Exploit

22 May 2025, 13:15

Type Values Removed Values Added
References
  • () https://www.mozilla.org/security/advisories/mfsa2025-40/ -
  • () https://www.mozilla.org/security/advisories/mfsa2025-41/ -
Summary (en) An attacker was able to perform an out-of-bounds read or write on a JavaScript `Promise` object. This vulnerability affects Firefox < 138.0.4, Firefox ESR < 128.10.1, and Firefox ESR < 115.23.1. (en) An attacker was able to perform an out-of-bounds read or write on a JavaScript `Promise` object. This vulnerability affects Firefox < 138.0.4, Firefox ESR < 128.10.1, Firefox ESR < 115.23.1, Thunderbird < 128.10.2, and Thunderbird < 138.0.2.

21 May 2025, 16:15

Type Values Removed Values Added
References
  • () https://www.vicarius.io/vsociety/posts/cve-2025-4918-detect-firefox-out-of-bounds-write -
  • () https://www.vicarius.io/vsociety/posts/cve-2025-4918-mitigate-firefox-out-of-bounds-write -

19 May 2025, 21:15

Type Values Removed Values Added
CVSS v2 : unknown
v3 : unknown 		v2 : unknown
v3 : 7.5
CWE CWE-125

19 May 2025, 13:35

Type Values Removed Values Added
Summary
  • (es) Un atacante logró realizar una lectura o escritura fuera de los límites en un objeto "Promise" de JavaScript. Esta vulnerabilidad afecta a Firefox (versión anterior a 138.0.4), Firefox ESR (versión anterior a 128.10.1) y Firefox ESR (versión anterior a 115.23.1).

18 May 2025, 20:15

Type Values Removed Values Added
References
  • () https://www.mozilla.org/security/advisories/mfsa2025-36/ -
  • () https://www.mozilla.org/security/advisories/mfsa2025-37/ -
Summary (en) An attacker was able to perform an out-of-bounds read or write on a JavaScript `Promise` object. This vulnerability affects Firefox ESR < 115.23.1. (en) An attacker was able to perform an out-of-bounds read or write on a JavaScript `Promise` object. This vulnerability affects Firefox < 138.0.4, Firefox ESR < 128.10.1, and Firefox ESR < 115.23.1.

17 May 2025, 22:15

Type Values Removed Values Added
New CVE
Information

Published : 2025-05-17 22:15

Updated : 2025-09-22 18:15

NVD link : CVE-2025-4918

Mitre link : CVE-2025-4918

CVE.ORG link : CVE-2025-4918

JSON object : View

Products Affected

mozilla

  • thunderbird
  • firefox
CWE
CWE-125

Out-of-bounds Read

CWE-787

Out-of-bounds Write