CVE-2019-9816
A possible vulnerability exists where type confusion can occur when manipulating JavaScript objects in object groups, allowing for the bypassing of security checks within these groups. *Note: this vulnerability has only been demonstrated with…
Does this matter?
A public exploit is published in Exploit-DB (verified), so the technical barrier is gone even though the severity is medium and EPSS is 6.2%. Treat it as high on anything reachable from the internet.
Description
A possible vulnerability exists where type confusion can occur when manipulating JavaScript objects in object groups, allowing for the bypassing of security checks within these groups. *Note: this vulnerability has only been demonstrated with UnboxedObjects, which are disabled by default on all supported releases.*. This vulnerability affects Thunderbird < 60.7, Firefox < 67, and Firefox ESR < 60.7.
- CVSS 3.0
- 5.9 MEDIUMCVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
- EPSS
- 6.15% probability · 93th percentile
- Public exploits
- 1 in Exploit-DB · verified · first 29 May 2019
- CISA KEV
- Not listed
- Weakness
- CWE-843
- Affected
- mozilla/firefox · mozilla/firefox esr · mozilla/thunderbird
- Source
- security@mozilla.org
EPSS moved from 4.9% on 21 September 2026 to 6.2% on 26 October 2026. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”.
Public exploits (1)
Entries in Exploit-DB that cite this CVE. Links go to the Exploit-DB page and to the file in the public repository; nothing is hosted here. A verified tick means the Exploit-DB team confirmed the exploit works against the stated version.
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=1536768Permissions Required
- https://www.mozilla.org/security/advisories/mfsa2019-13/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2019-14/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2019-15/Vendor Advisory
- https://bugzilla.mozilla.org/show_bug.cgi?id=1536768Permissions Required
- https://www.mozilla.org/security/advisories/mfsa2019-13/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2019-14/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2019-15/Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.