CVE-2019-9795
A vulnerability where type-confusion in the IonMonkey just-in-time (JIT) compiler could potentially be used by malicious JavaScript to trigger a potentially exploitable crash.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.70%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
A vulnerability where type-confusion in the IonMonkey just-in-time (JIT) compiler could potentially be used by malicious JavaScript to trigger a potentially exploitable crash. This vulnerability affects Thunderbird < 60.6, Firefox ESR < 60.6, and Firefox < 66.
- CVSS 3.0
- 9.8 CRITICALCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 1.70% probability · 77th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-617, CWE-843
- Affected
- mozilla/firefox · mozilla/firefox esr · mozilla/thunderbird
- Source
- security@mozilla.org
EPSS 1.7% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://access.redhat.com/errata/RHSA-2019:0966
- https://access.redhat.com/errata/RHSA-2019:1144
- https://bugzilla.mozilla.org/show_bug.cgi?id=1514682Issue Tracking, Permissions Required, Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2019-07/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2019-08/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2019-11/Vendor Advisory
- https://access.redhat.com/errata/RHSA-2019:0966
- https://access.redhat.com/errata/RHSA-2019:1144
- https://bugzilla.mozilla.org/show_bug.cgi?id=1514682Issue Tracking, Permissions Required, Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2019-07/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2019-08/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2019-11/Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.