Findings

CVE-2026-2771

Undefined behavior in the DOM: Core & HTML component.

Published Feb 24, 2026 · updated Sep 21, 2026 · mozilla firefox

Undefined behavior in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 148, Firefox ESR 115.33, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Feb 24, 2026 · NIST NVD

    Detected

    Undefined behavior in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 148, Firefox ESR 115.33, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.

  2. Sep 21, 2026 · NIST NVD

    Updated

    Undefined behavior in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 148, Firefox ESR 115.33, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.

Affected

  • cpe mozilla/firefoxversion unspecified
  • cpe mozilla/thunderbirdversion unspecified

Sources

  • CVE.orgVulnerability recordCVE-2026-2771

    Official CVE identifier

    cve.org
  • NIST NVDVulnerability recordCVE-2026-2771

    Undefined behavior in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 148, Firefox ESR 115.33, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.

    nvd.nist.gov

References