CVE-2026-4712
Published: 24 March 2026
Description
Information disclosure in the Widget: Cocoa component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.
Mitigating Controls (NIST 800-53 r5)AI
Directly mandates timely patching of known flaws like CVE-2026-4712, as fixed in specified Firefox and Thunderbird versions.
Enables vulnerability scanning to identify systems running vulnerable versions of Firefox, ESR, or Thunderbird affected by this information disclosure.
Requires monitoring Mozilla security advisories (e.g., MFSA 2026-20) to promptly learn of and apply patches for this CVE.
Security SummaryAI
CVE-2026-4712 is an information disclosure vulnerability (CWE-200) in the Widget: Cocoa component, affecting Mozilla Firefox, Firefox ESR, and Thunderbird. The issue enables unauthorized access to sensitive data and was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.
Remote attackers can exploit this vulnerability over the network with low attack complexity, requiring no privileges, no user interaction, and without altering the scope of impact. Successful exploitation results in high confidentiality impact, allowing disclosure of sensitive information from affected systems, while integrity and availability remain unaffected. The CVSS v3.1 base score is 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N).
Mozilla's security advisories (MFSA 2026-20, MFSA 2026-22, MFSA 2026-23, and MFSA 2026-24), along with Bugzilla entry 2017666, document the vulnerability and recommend updating to the patched versions as the primary mitigation.
Details
- CWE(s)
Affected Products
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Remote unauthenticated info disclosure (CWE-200) with high confidentiality impact directly enables collection of sensitive data from the local system on affected browsers/email clients.