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CVE-2019-9792
CRITICAL
The IonMonkey just-in-time (JIT) compiler can leak an internal JS_OPTIMIZED_OUT magic value to the running script during a bailout. This magic value can then be used by JavaScript to achieve memory corruption, which results in a potentially exploitable crash. This vulnerability affects Thunderbird < 60.6, Firefox ESR < 60.6, and Firefox < 66.
Published: Apr 26, 2019
Modified: Jun 17, 2026
CWE-787
CVSS Metrics
CVSSv3
Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
NONE
User Interaction:
NONE
Scope:
UNCHANGED
Confidentiality Impact:
HIGH
Integrity Impact:
HIGH
Availability Impact:
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Affected Products (11)
| Vendor | Product | Version |
|---|---|---|
| mozilla | firefox | * < 60.6.0 |
| mozilla | firefox | * < 66.0 |
| mozilla | thunderbird | * < 60.6.0 |
| redhat | enterprise_linux | 8.0 |
| redhat | enterprise_linux_eus | 8.1 |
| redhat | enterprise_linux_eus | 8.2 |
| redhat | enterprise_linux_eus | 8.4 |
| redhat | enterprise_linux_server_aus | 8.2 |
| redhat | enterprise_linux_server_aus | 8.4 |
| redhat | enterprise_linux_server_tus | 8.2 |
| redhat | enterprise_linux_server_tus | 8.4 |
GitHub Security Advisory GHSA-83fw-4w4c-4v29
The IonMonkey just-in-time (JIT) compiler can leak an internal JS_OPTIMIZED_OUT magic value to...
References (14)
- http://packetstormsecurity.com/files/153106/Spidermonkey-IonMonkey-JS_OPTIMIZED_OUT-Value-Leak.html Exploit, Third Party Advisory, VDB Entry
- https://access.redhat.com/errata/RHSA-2019:0966 Third Party Advisory
- https://access.redhat.com/errata/RHSA-2019:1144 Third Party Advisory
- https://bugzilla.mozilla.org/show_bug.cgi?id=1532599 Exploit, Issue Tracking, 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
- http://packetstormsecurity.com/files/153106/Spidermonkey-IonMonkey-JS_OPTIMIZED_OUT-Value-Leak.html Exploit, Third Party Advisory, VDB Entry
- https://access.redhat.com/errata/RHSA-2019:0966 Third Party Advisory
- https://access.redhat.com/errata/RHSA-2019:1144 Third Party Advisory
- https://bugzilla.mozilla.org/show_bug.cgi?id=1532599 Exploit, Issue Tracking, 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
Risk Scores
CVSS Score
9.8 / 10
EPSS Score
13.20%
Top 4% most likely to be exploited
Threat Score
43.2 / 100
Data Sources
NVD
EPSS
GitHub