CVE-2026-16356: Vulnerability in Mozilla Firefox
CVE-2026-16356 is a critical use-after-free vulnerability in the Disability Access APIs component of Mozilla Firefox and Thunderbird. This flaw allows sandbox escape, potentially enabling an attacker to execute arbitrary code outside the browser's sandbox. The vulnerability is fixed in Firefox 153, Firefox ESR 115.38, Firefox ESR 140.13, Thunderbird 153, and Thunderbird 140.13. The CVSS score is 9.8, indicating a critical severity with network attack vector, no privileges or user interaction required, and high impact on confidentiality, integrity, and availability.
AI Analysis
Technical Summary
CVE-2026-16356 is a sandbox escape vulnerability caused by a use-after-free condition in the Disability Access APIs component of Mozilla Firefox and Thunderbird. This vulnerability allows an attacker to bypass sandbox restrictions, potentially leading to arbitrary code execution. It affects Firefox versions prior to 153, Firefox ESR versions prior to 115.38 and 140.13, and corresponding Thunderbird versions. Mozilla has addressed this issue in Firefox 153, Firefox ESR 115.38, Firefox ESR 140.13, Thunderbird 153, and Thunderbird 140.13. The vulnerability has a CVSS v3.1 base score of 9.8, reflecting critical impact and ease of exploitation without privileges or user interaction. Vendor advisories confirm the fix and provide detailed references to the underlying bugs.
Potential Impact
Successful exploitation of this vulnerability allows an attacker to escape the sandbox environment of Firefox or Thunderbird, potentially leading to arbitrary code execution with the privileges of the user running the application. The impact includes full compromise of confidentiality, integrity, and availability of the affected system. The vulnerability is remotely exploitable without authentication or user interaction, making it highly severe.
Mitigation Recommendations
This vulnerability is fixed in Firefox 153, Firefox ESR 115.38, Firefox ESR 140.13, Thunderbird 153, and Thunderbird 140.13. Users and administrators should update affected products to these versions or later to mitigate the risk. No additional mitigation steps are required beyond applying the official patches provided by Mozilla.
CVE-2026-16356: Vulnerability in Mozilla Firefox
Description
CVE-2026-16356 is a critical use-after-free vulnerability in the Disability Access APIs component of Mozilla Firefox and Thunderbird. This flaw allows sandbox escape, potentially enabling an attacker to execute arbitrary code outside the browser's sandbox. The vulnerability is fixed in Firefox 153, Firefox ESR 115.38, Firefox ESR 140.13, Thunderbird 153, and Thunderbird 140.13. The CVSS score is 9.8, indicating a critical severity with network attack vector, no privileges or user interaction required, and high impact on confidentiality, integrity, and availability.
CVSS v3.1
Score 9.8critical
Affected software
pkg:github/mozilla/firefox-esrRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-16356 is a sandbox escape vulnerability caused by a use-after-free condition in the Disability Access APIs component of Mozilla Firefox and Thunderbird. This vulnerability allows an attacker to bypass sandbox restrictions, potentially leading to arbitrary code execution. It affects Firefox versions prior to 153, Firefox ESR versions prior to 115.38 and 140.13, and corresponding Thunderbird versions. Mozilla has addressed this issue in Firefox 153, Firefox ESR 115.38, Firefox ESR 140.13, Thunderbird 153, and Thunderbird 140.13. The vulnerability has a CVSS v3.1 base score of 9.8, reflecting critical impact and ease of exploitation without privileges or user interaction. Vendor advisories confirm the fix and provide detailed references to the underlying bugs.
Potential Impact
Successful exploitation of this vulnerability allows an attacker to escape the sandbox environment of Firefox or Thunderbird, potentially leading to arbitrary code execution with the privileges of the user running the application. The impact includes full compromise of confidentiality, integrity, and availability of the affected system. The vulnerability is remotely exploitable without authentication or user interaction, making it highly severe.
Mitigation Recommendations
This vulnerability is fixed in Firefox 153, Firefox ESR 115.38, Firefox ESR 140.13, Thunderbird 153, and Thunderbird 140.13. Users and administrators should update affected products to these versions or later to mitigate the risk. No additional mitigation steps are required beyond applying the official patches provided by Mozilla.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mozilla
- Date Reserved
- 2026-07-20T21:56:01.537Z
- Cvss Version
- null
- State
- PUBLISHED
- Remediation Level
- null
- Vendor Advisory Urls
- [{"url":"https://www.mozilla.org/security/advisories/mfsa2026-68/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-69/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-70/","vendor":"Mozilla"}]
Threat ID: 6a5f6cb92a4a8d598926242c
Added to database: 07/21/2026, 12:57:29 UTC
Last enriched: 07/30/2026, 11:09:44 UTC
Last updated: 09/02/2026, 22:52:09 UTC
Views: 73
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