Type confusion in Mozilla Thunderbird
Priority MEDIUM 61CWE-843Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-843 and the CVSS impact.
Summary
The type inference system allows the compilation of functions that can cause type confusions between arbitrary objects when compiled through the IonMonkey just-in-time (JIT) compiler and when the constructor function is entered through on-stack replacement (OSR). This allows for possible arbitrary reading and writing of objects during an exploitable crash. This vulnerability affects Thunderbird < 60.6, Firefox ESR < 60.6, and Firefox < 66.
Why it matters now
EPSS 0.19915 97th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed Thunderbird (Mozilla): 60.6Firefox ESR (Mozilla): 60.6+1 more productRed Hat: 6 advisories
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Mozilla | Thunderbird | before 60.6 | 60.6 | Patch available | CNA |
| Mozilla | Firefox ESR | before 60.6 | 60.6 | Patch available | CNA |
| Mozilla | Firefox | before 66 | 66 | Patch available | CNA |
- Thunderbird VendorMozilla Affected before 60.6 Fixed in 60.6 Patch available CNA
- Firefox ESR VendorMozilla Affected before 60.6 Fixed in 60.6 Patch available CNA
- Firefox VendorMozilla Affected before 66 Fixed in 66 Patch available CNA
CPE configurations NVD · 10
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:* | before 60.6.0; before 66.0 | Vulnerable | Mozilla |
| cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:* | before 60.6.0 | Vulnerable | Mozilla |
| cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:* | 8.0 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_eus:8.1:*:*:*:*:*:*:* | 8.1 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_eus:8.2:*:*:*:*:*:*:* | 8.2 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_eus:8.4:*:*:*:*:*:*:* | 8.4 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_server_aus:8.2:*:*:*:*:*:*:* | 8.2 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_server_aus:8.4:*:*:*:*:*:*:* | 8.4 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_server_tus:8.2:*:*:*:*:*:*:* | 8.2 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_server_tus:8.4:*:*:*:*:*:*:* | 8.4 | Vulnerable | Red Hat |
- cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:* Versions before 60.6.0; before 66.0 Vulnerable ·Mozilla
- cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:* Versions before 60.6.0 Vulnerable ·Mozilla
- cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:* Versions 8.0 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_eus:8.1:*:*:*:*:*:*:* Versions 8.1 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_eus:8.2:*:*:*:*:*:*:* Versions 8.2 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_eus:8.4:*:*:*:*:*:*:* Versions 8.4 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_server_aus:8.2:*:*:*:*:*:*:* Versions 8.2 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_server_aus:8.4:*:*:*:*:*:*:* Versions 8.4 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_server_tus:8.2:*:*:*:*:*:*:* Versions 8.2 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_server_tus:8.4:*:*:*:*:*:*:* Versions 8.4 Vulnerable ·Red Hat
Remediation
- Fix · CNA Thunderbird (Mozilla) Fixed in 60.6
- Fix · CNA Firefox ESR (Mozilla) Fixed in 60.6
- Fix · CNA Firefox (Mozilla) Fixed in 66
Red Hat 6 advisories
- RHSA-2019:1144 Released 2019-05-13 · Red Hat rating Importantthunderbird security update
- Red Hat Enterprise Linux AppStream (v. 8) thunderbird-60.6.1-1.el8
- RHSA-2019:0966 Released 2019-05-07 · Red Hat rating Criticalfirefox security update
- Red Hat Enterprise Linux AppStream (v. 8) firefox-60.6.1-1.el8
- RHSA-2019:0681 Released 2019-03-28 · Red Hat rating Importantthunderbird security update
- Red Hat Enterprise Linux Client (v. 7) thunderbird-60.6.1-1.el7_6
- Red Hat Enterprise Linux Server Optional (v. 7) thunderbird-60.6.1-1.el7_6
- Red Hat Enterprise Linux Workstation (v. 7) thunderbird-60.6.1-1.el7_6
- Red Hat Enterprise Linux for ARM and IBM Power LE (POWER9) Server Optional (v. 7) thunderbird-60.6.1-1.el7_6
Show 3 more Red Hat advisories
- RHSA-2019:0680 Released 2019-03-28 · Red Hat rating Importantthunderbird security update
- Red Hat Enterprise Linux Desktop (v. 6) thunderbird-60.6.1-1.el6_10
- Red Hat Enterprise Linux Server Optional (v. 6) thunderbird-60.6.1-1.el6_10
- Red Hat Enterprise Linux Workstation (v. 6) thunderbird-60.6.1-1.el6_10
- RHSA-2019:0623 Released 2019-03-20 · Red Hat rating Criticalfirefox security update
- Red Hat Enterprise Linux Desktop (v. 6) firefox-60.6.0-3.el6_10
- Red Hat Enterprise Linux Desktop Optional (v. 6) firefox-60.6.0-3.el6_10
- Red Hat Enterprise Linux HPC Node Optional (v. 6) firefox-60.6.0-3.el6_10
- Red Hat Enterprise Linux Server (v. 6) firefox-60.6.0-3.el6_10
- Red Hat Enterprise Linux Server Optional (v. 6) firefox-60.6.0-3.el6_10
- Red Hat Enterprise Linux Workstation (v. 6) firefox-60.6.0-3.el6_10
- Red Hat Enterprise Linux Workstation Optional (v. 6) firefox-60.6.0-3.el6_10
- RHSA-2019:0622 Released 2019-03-20 · Red Hat rating Criticalfirefox security update
- Red Hat Enterprise Linux Client (v. 7) firefox-60.6.0-3.el7_6
- Red Hat Enterprise Linux Client Optional (v. 7) firefox-60.6.0-3.el7_6
- Red Hat Enterprise Linux Server (v. 7) firefox-60.6.0-3.el7_6
- Red Hat Enterprise Linux Server Optional (v. 7) firefox-60.6.0-3.el7_6
- Red Hat Enterprise Linux Workstation (v. 7) firefox-60.6.0-3.el7_6
- Red Hat Enterprise Linux Workstation Optional (v. 7) firefox-60.6.0-3.el7_6
- Red Hat Enterprise Linux for ARM and IBM Power LE (POWER9) Server (v. 7) firefox-60.6.0-3.el7_6
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Release ·
Mozilla Firefox 66
21 records Highest priority Priority MEDIUM 10 MEDIUM, 11 LOW
Other records, highest priority first
- TI-2019-07178 Out-of-bounds write in Mozilla ThunderbirdPriority MEDIUM 57
- TI-2019-07190 OS command injection in Mozilla FirefoxPriority MEDIUM 46
- TI-2019-07182 Use after free in Mozilla ThunderbirdPriority MEDIUM 46
- Release ·
Mozilla Firefox ESR, Thunderbird 60.6
9 records Highest priority Priority MEDIUM 7 MEDIUM, 2 LOW
Other records, highest priority first
- TI-2019-07178 Out-of-bounds write in Mozilla ThunderbirdPriority MEDIUM 57
- TI-2019-07182 Use after free in Mozilla ThunderbirdPriority MEDIUM 46
- TI-2019-07180 A vulnerability was discovered where specific command line arguments are not properly…Priority MEDIUM 46
Vendor assessments
Red Hat
Red Hat rating: Critical. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux AppStream (v. 8) | Fixed | RHSA-2019:0966, RHSA-2019:1144 |
| Red Hat Enterprise Linux Client (v. 7) | Fixed | RHSA-2019:0622, RHSA-2019:0681 |
| Red Hat Enterprise Linux Client Optional (v. 7) | Fixed | RHSA-2019:0622 |
| Red Hat Enterprise Linux Desktop (v. 6) | Fixed | RHSA-2019:0623, RHSA-2019:0680 |
| Red Hat Enterprise Linux Desktop Optional (v. 6) | Fixed | RHSA-2019:0623 |
| Red Hat Enterprise Linux HPC Node Optional (v. 6) | Fixed | RHSA-2019:0623 |
| Red Hat Enterprise Linux Server (v. 6) | Fixed | RHSA-2019:0623 |
| Red Hat Enterprise Linux Server (v. 7) | Fixed | RHSA-2019:0622 |
| Red Hat Enterprise Linux Server Optional (v. 6) | Fixed | RHSA-2019:0623, RHSA-2019:0680 |
| Red Hat Enterprise Linux Server Optional (v. 7) | Fixed | RHSA-2019:0622, RHSA-2019:0681 |
| Red Hat Enterprise Linux Workstation (v. 6) | Fixed | RHSA-2019:0623, RHSA-2019:0680 |
| Red Hat Enterprise Linux Workstation (v. 7) | Fixed | RHSA-2019:0622, RHSA-2019:0681 |
| Red Hat Enterprise Linux Workstation Optional (v. 6) | Fixed | RHSA-2019:0623 |
| Red Hat Enterprise Linux Workstation Optional (v. 7) | Fixed | RHSA-2019:0622 |
| Red Hat Enterprise Linux for ARM and IBM Power LE (POWER9) Server (v. 7) | Fixed | RHSA-2019:0622 |
| Red Hat Enterprise Linux for ARM and IBM Power LE (POWER9) Server Optional (v. 7) | Fixed | RHSA-2019:0681 |
Timeline
- 2026-10-02 Threatist record created from CVE-2019-9791
- 2026-10-03 Alias added: GHSA-9r58-49jg-hrq7
References
More Mozilla Firefox vulnerabilities
- TI-2024-08981 Use after free in Mozilla Firefox KEVCVSS 3.1CRITICAL 9.8
- TI-2022-09832 Use after free in Mozilla Firefox KEVCVSS 3.1CRITICAL 9.6
- TI-2019-08769 Improper input validation in Mozilla Firefox ESR KEVCVSS 3.1CRITICAL 10.0
- TI-2010-03577 Mozilla Firefox 3.5.x through 3.5.14 and 3.6.x through 3.6.11, Thunderbird 3.1.6 before… KEVCVSS 3.1CRITICAL 9.8
- TI-2023-04799 Out-of-bounds write in Google Chrome KEVCVSS 3.1HIGH 8.8
- TI-2023-04477 Out-of-bounds write in Google Chrome KEVCVSS 3.1HIGH 8.8
Sources
- CVE-2019-9791 · CVE Program
- CVE-2019-9791 · NVD
- FIRST EPSS
- GHSA-9r58-49jg-hrq7 · GitHub Advisory Database · CC BY 4.0
- CVE-2019-9791 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences