Description
Use-after-free in the DOM: Bindings (WebIDL) component. This vulnerability was fixed in Firefox 148, Firefox ESR 115.33, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.
Published: 2026-02-24
Score: 8.8 High
EPSS: < 1% Very Low
KEV: No
Impact: Remote Code Execution
Action: Immediate Patch
AI Analysis

Impact

A use‑after‑free flaw was discovered in the DOM: Bindings (WebIDL) component. This vulnerability can lead to memory corruption that allows an attacker to execute arbitrary code or crash the process. The flaw is classified as CWE‑416.

Affected Systems

Mozilla Firefox and Thunderbird, including all releases prior to Firefox 148, Firefox ESR 115.33, Firefox ESR 140.8, Thunderbird 148, and Thunderbird ESR 140.8.

Risk and Exploitability

Based on the description, the likely attack vector is the processing of crafted WebIDL code, typically supplied by a malicious web page or a targeted email attachment, to trigger the use‑after‑free. The CVSS base score is 8.8, marking it high severity, but the EPSS score is below 1 % indicating a very low expected exploitation probability. The vulnerability is not listed in the CISA KEV catalog. Attackers would need to supply crafted WebIDL code, typically via a malicious web page or a targeted email attachment, to trigger the use‑after‑free; the flaw is exploitable only when the vulnerable version is running and the malicious content is processed.

Generated by OpenCVE AI on April 15, 2026 at 16:11 UTC.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • Upgrade Firefox to version 148 or later, or to Firefox ESR 115.33 or 140.8, and upgrade Thunderbird to version 148 or later, or to Thunderbird ESR 140.8. This is the official solution provided by Mozilla.
  • Enable automatic security updates so that future patches are applied as soon as they become available.
  • If immediate upgrading is not possible, restrict the loading of untrusted web content by tightening browser privacy settings or applying content‑security‑policy rules; note that no official workaround is available.

Generated by OpenCVE AI on April 15, 2026 at 16:11 UTC.

Tracking

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Advisories
Source ID Title
Debian DLA Debian DLA DLA-4495-1 thunderbird security update
Debian DLA Debian DLA DLA-4496-1 firefox-esr security update
Debian DSA Debian DSA DSA-6148-1 firefox-esr security update
Debian DSA Debian DSA DSA-6152-1 thunderbird security update
History

Mon, 13 Apr 2026 14:30:00 +0000

Type Values Removed Values Added
Description Use-after-free in the DOM: Bindings (WebIDL) component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8. Use-after-free in the DOM: Bindings (WebIDL) component. This vulnerability was fixed in Firefox 148, Firefox ESR 115.33, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.

Sat, 28 Feb 2026 03:15:00 +0000

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}

 ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

cvssV3_1

{'score': 8.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H'}

Wed, 25 Feb 2026 16:45:00 +0000

Type Values Removed Values Added
Weaknesses CWE-416
CPEs 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:*:*:*:*:esr:*:*:*
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H'}

 cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}

Wed, 25 Feb 2026 12:00:00 +0000

Type Values Removed Values Added
First Time appeared Mozilla
Mozilla firefox
Mozilla firefox Esr
Mozilla thunderbird
Vendors & Products Mozilla
Mozilla firefox
Mozilla firefox Esr
Mozilla thunderbird

Wed, 25 Feb 2026 00:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

 cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H'}

threat_severity

Important

Tue, 24 Feb 2026 18:00:00 +0000

Type Values Removed Values Added
Description Use-after-free in the DOM: Bindings (WebIDL) component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, and Firefox ESR < 140.8. Use-after-free in the DOM: Bindings (WebIDL) component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.
References

Tue, 24 Feb 2026 14:00:00 +0000

Type Values Removed Values Added
Description Use-after-free in the DOM: Bindings (WebIDL) component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, and Firefox ESR < 140.8.
Title Use-after-free in the DOM: Bindings (WebIDL) component
References

Subscriptions

Mozilla Firefox Firefox Esr Thunderbird
cve-icon MITRE

Status: PUBLISHED

Assigner: mozilla

Published:

Updated: 2026-04-13T13:52:34.610Z

Reserved: 2026-02-19T15:05:46.768Z

Link: CVE-2026-2770

cve-icon Vulnrichment

Updated: 2026-02-26T20:16:10.154Z

cve-icon NVD

Status : Modified

Published: 2026-02-24T14:16:25.397

Modified: 2026-04-13T15:17:23.423

Link: CVE-2026-2770

cve-icon Redhat

Severity : Important

Publid Date: 2026-02-24T13:33:07Z

Links: CVE-2026-2770 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-04-15T17:15:10Z

Weaknesses