CVE-2025-4918

CRITICAL EPSS 94.6%
Published May 17, 20251y ago · Modified Jun 17, 20261w ago
9.8 CVSS 3.1
Critical
Find Similar
Published May 17, 2025 1y ago
Last Modified Jun 17, 2026 1w ago

Description

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.

CVSS Details

Base Score
9.8
Exploitability
3.9
Impact
5.9
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality High
Integrity High
Availability High

Threat Intelligence

EPSS Exploit Probability
94.6% percentile
Exploit & Patch Status
Public Exploit Known
No Patch Available

Weaknesses 2

CWE-125 Out-of-bounds Read Memory Safety
CWE-787 Out-of-bounds Write Memory Safety

Affected Products 5

VendorProductVersionRange
mozillafirefox* <115.23.1
mozillafirefox* <138.0.4
mozillafirefox*≥116.0  –  <128.10.1
mozillathunderbird* <128.10.2
mozillathunderbird*≥138.0  –  <138.0.2

References 10

  • bugzilla.mozilla.org https://bugzilla.mozilla.org/show_bug.cgi?id=1966612
    Permissions Required
  • lists.debian.org https://lists.debian.org/debian-lts-announce/2025/05/msg00024.html
  • lists.debian.org https://lists.debian.org/debian-lts-announce/2025/05/msg00046.html
  • mozilla.org https://www.mozilla.org/security/advisories/mfsa2025-36/
    Vendor Advisory
  • mozilla.org https://www.mozilla.org/security/advisories/mfsa2025-37/
    Vendor Advisory
  • mozilla.org https://www.mozilla.org/security/advisories/mfsa2025-38/
    Vendor Advisory
  • mozilla.org https://www.mozilla.org/security/advisories/mfsa2025-40/
    Vendor Advisory
  • mozilla.org https://www.mozilla.org/security/advisories/mfsa2025-41/
    Vendor Advisory
  • vicarius.io https://www.vicarius.io/vsociety/posts/cve-2025-4918-detect-firefox-out-of-bounds-write
    ExploitThird Party Advisory
  • vicarius.io https://www.vicarius.io/vsociety/posts/cve-2025-4918-mitigate-firefox-out-of-bounds-write
    ExploitThird Party Advisory

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.