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
References
Link Providers
https://access.redhat.com/errata/RHSA-2026:3338 cve-icon
https://access.redhat.com/errata/RHSA-2026:3339 cve-icon
https://access.redhat.com/errata/RHSA-2026:3361 cve-icon
https://access.redhat.com/errata/RHSA-2026:3491 cve-icon
https://access.redhat.com/errata/RHSA-2026:3492 cve-icon
https://access.redhat.com/errata/RHSA-2026:3493 cve-icon
https://access.redhat.com/errata/RHSA-2026:3494 cve-icon
https://access.redhat.com/errata/RHSA-2026:3495 cve-icon
https://access.redhat.com/errata/RHSA-2026:3496 cve-icon
https://access.redhat.com/errata/RHSA-2026:3497 cve-icon
https://access.redhat.com/errata/RHSA-2026:3515 cve-icon
https://access.redhat.com/errata/RHSA-2026:3516 cve-icon
https://access.redhat.com/errata/RHSA-2026:3517 cve-icon
https://access.redhat.com/errata/RHSA-2026:3976 cve-icon
https://access.redhat.com/errata/RHSA-2026:3978 cve-icon
https://access.redhat.com/errata/RHSA-2026:3979 cve-icon
https://access.redhat.com/errata/RHSA-2026:3980 cve-icon
https://access.redhat.com/errata/RHSA-2026:3981 cve-icon
https://access.redhat.com/errata/RHSA-2026:3982 cve-icon
https://access.redhat.com/errata/RHSA-2026:3983 cve-icon
https://access.redhat.com/errata/RHSA-2026:3984 cve-icon
https://access.redhat.com/errata/RHSA-2026:4022 cve-icon
https://access.redhat.com/errata/RHSA-2026:4152 cve-icon
https://access.redhat.com/errata/RHSA-2026:4260 cve-icon
https://access.redhat.com/errata/RHSA-2026:4432 cve-icon
https://access.redhat.com/security/cve/CVE-2026-2770 cve-icon
https://bugzilla.mozilla.org/show_bug.cgi?id=2014585 cve-icon cve-icon
https://bugzilla.redhat.com/show_bug.cgi?id=2442343 cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2026-2770 cve-icon
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-2770.json cve-icon
https://www.cve.org/CVERecord?id=CVE-2026-2770 cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-13/ cve-icon cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-14/ cve-icon cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-15/ cve-icon cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-15/#CVE-2026-2770 cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-16/ cve-icon cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-17/ cve-icon cve-icon
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: 2026-07-15T01:13:23.477Z

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

Link: CVE-2026-2770

cve-icon Vulnrichment

Updated: 2026-07-15T01:13:23.477Z

cve-icon NVD

Status : Modified

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

Modified: 2026-07-15T02:19:37.997

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