Out-of-bounds write in Mozilla Thunderbird
Priority MEDIUM 42CWE-787Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 16 fixed, 1 without a fix
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-787 and the CVSS impact.
Summary
Mozilla developers reported memory safety bugs present in Firefox 76 and Firefox ESR 68.8. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Thunderbird < 68.9.0, Firefox < 77, and Firefox ESR < 68.9.
Why it matters now
EPSS 0.01729 77th percentileScored 2026-11-07
Fix Partial Thunderbird (Mozilla): 68.9.0Firefox (Mozilla): 77+1 more productRed Hat: 10 advisoriesRed Hat: 16 fixed, 1 without a fix
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 68.9.0 | 68.9.0 | Patch available | CNA |
| Mozilla | Firefox | before 77 | 77 | Patch available | CNA |
| Mozilla | Firefox ESR | before 68.9 | 68.9 | Patch available | CNA |
- Thunderbird VendorMozilla Affected before 68.9.0 Fixed in 68.9.0 Patch available CNA
- Firefox VendorMozilla Affected before 77 Fixed in 77 Patch available CNA
- Firefox ESR VendorMozilla Affected before 68.9 Fixed in 68.9 Patch available CNA
CPE configurations NVD · 6
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:* | before 76.0 | Vulnerable | Mozilla |
| cpe:2.3:a:mozilla:firefox_esr:*:*:*:*:*:*:*:* | before 68.8.0 | Vulnerable | Mozilla |
| cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:esm:*:*:* | 16.04 | Vulnerable | Canonical |
| cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:* | 18.04 | Vulnerable | Canonical |
| cpe:2.3:o:canonical:ubuntu_linux:19.10:*:*:*:*:*:*:* | 19.10 | Vulnerable | Canonical |
| cpe:2.3:o:canonical:ubuntu_linux:20.04:*:*:*:lts:*:*:* | 20.04 | Vulnerable | Canonical |
- cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:* Versions before 76.0 Vulnerable ·Mozilla
- cpe:2.3:a:mozilla:firefox_esr:*:*:*:*:*:*:*:* Versions before 68.8.0 Vulnerable ·Mozilla
- cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:esm:*:*:* Versions 16.04 Vulnerable ·Canonical
- cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:* Versions 18.04 Vulnerable ·Canonical
- cpe:2.3:o:canonical:ubuntu_linux:19.10:*:*:*:*:*:*:* Versions 19.10 Vulnerable ·Canonical
- cpe:2.3:o:canonical:ubuntu_linux:20.04:*:*:*:lts:*:*:* Versions 20.04 Vulnerable ·Canonical
Remediation
- Fix · CNA Thunderbird (Mozilla) Fixed in 68.9.0
- Fix · CNA Firefox (Mozilla) Fixed in 77
- Fix · CNA Firefox ESR (Mozilla) Fixed in 68.9
Red Hat 10 advisories
- RHSA-2020:2615 Released 2020-06-22 · Red Hat rating Importantthunderbird security update
- Red Hat Enterprise Linux Client (v. 7) thunderbird-68.9.0-1.el7_8
- Red Hat Enterprise Linux Server Optional (v. 7) thunderbird-68.9.0-1.el7_8
- Red Hat Enterprise Linux Workstation (v. 7) thunderbird-68.9.0-1.el7_8
- RHSA-2020:2614 Released 2020-06-22 · Red Hat rating Importantthunderbird security update
- Red Hat Enterprise Linux AppStream (v. 8) thunderbird-68.9.0-1.el8_2
- RHSA-2020:2613 Released 2020-06-19 · Red Hat rating Importantthunderbird security update
- Red Hat Enterprise Linux Desktop (v. 6) thunderbird-68.9.0-1.el6_10
- Red Hat Enterprise Linux Server Optional (v. 6) thunderbird-68.9.0-1.el6_10
- Red Hat Enterprise Linux Workstation (v. 6) thunderbird-68.9.0-1.el6_10
Show 7 more Red Hat advisories
- RHSA-2020:2611 Released 2020-06-19 · Red Hat rating Importantthunderbird security update
- Red Hat Enterprise Linux AppStream EUS (v. 8.1) thunderbird-68.9.0-1.el8_1
- RHSA-2020:2616 Released 2020-06-19 · Red Hat rating Importantthunderbird security update
- Red Hat Enterprise Linux AppStream E4S (v. 8.0) thunderbird-68.9.0-1.el8_0
- RHSA-2020:2381 Released 2020-06-03 · Red Hat rating Importantfirefox security update
- Red Hat Enterprise Linux Client (v. 7) firefox-68.9.0-1.el7_8
- Red Hat Enterprise Linux Client Optional (v. 7) firefox-68.9.0-1.el7_8
- Red Hat Enterprise Linux Server (v. 7) firefox-68.9.0-1.el7_8
- Red Hat Enterprise Linux Server Optional (v. 7) firefox-68.9.0-1.el7_8
- Red Hat Enterprise Linux Workstation (v. 7) firefox-68.9.0-1.el7_8
- Red Hat Enterprise Linux Workstation Optional (v. 7) firefox-68.9.0-1.el7_8
- RHSA-2020:2382 Released 2020-06-03 · Red Hat rating Importantfirefox security update
- Red Hat Enterprise Linux AppStream E4S (v. 8.0) firefox-68.9.0-1.el8_0
- RHSA-2020:2378 Released 2020-06-03 · Red Hat rating Importantfirefox security update
- Red Hat Enterprise Linux Desktop (v. 6) firefox-68.9.0-1.el6_10
- Red Hat Enterprise Linux Desktop Optional (v. 6) firefox-68.9.0-1.el6_10
- Red Hat Enterprise Linux HPC Node Optional (v. 6) firefox-68.9.0-1.el6_10
- Red Hat Enterprise Linux Server (v. 6) firefox-68.9.0-1.el6_10
- Red Hat Enterprise Linux Server Optional (v. 6) firefox-68.9.0-1.el6_10
- Red Hat Enterprise Linux Workstation (v. 6) firefox-68.9.0-1.el6_10
- Red Hat Enterprise Linux Workstation Optional (v. 6) firefox-68.9.0-1.el6_10
- RHSA-2020:2380 Released 2020-06-03 · Red Hat rating Importantfirefox security update
- Red Hat Enterprise Linux AppStream EUS (v. 8.1) firefox-68.9.0-1.el8_1
- RHSA-2020:2379 Released 2020-06-03 · Red Hat rating Importantfirefox security update
- Red Hat Enterprise Linux AppStream (v. 8) firefox-68.9.0-1.el8_2
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Advisory ·
Mozilla Firefox, Firefox ESR, Thunderbird — USN-4421-1
10 records Highest priority Priority MEDIUM 5 MEDIUM, 5 LOW
Other records, highest priority first
- TI-2020-09937 Use after free in Mozilla Firefox ESRPriority MEDIUM 43
- TI-2020-09935 Reachable assertion in Mozilla Firefox ESRPriority MEDIUM 43
- TI-2020-09938 Race condition in Mozilla Firefox ESRPriority MEDIUM 42
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 5 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux AppStream (v. 8) | Fixed | RHSA-2020:2379, RHSA-2020:2614 |
| Red Hat Enterprise Linux AppStream E4S (v. 8.0) | Fixed | RHSA-2020:2382, RHSA-2020:2616 |
| Red Hat Enterprise Linux AppStream EUS (v. 8.1) | Fixed | RHSA-2020:2380, RHSA-2020:2611 |
| Red Hat Enterprise Linux Client (v. 7) | Fixed | RHSA-2020:2381, RHSA-2020:2615 |
| Red Hat Enterprise Linux Client Optional (v. 7) | Fixed | RHSA-2020:2381 |
| Red Hat Enterprise Linux Desktop (v. 6) | Fixed | RHSA-2020:2378, RHSA-2020:2613 |
| Red Hat Enterprise Linux Desktop Optional (v. 6) | Fixed | RHSA-2020:2378 |
| Red Hat Enterprise Linux HPC Node Optional (v. 6) | Fixed | RHSA-2020:2378 |
| Red Hat Enterprise Linux Server (v. 6) | Fixed | RHSA-2020:2378 |
| Red Hat Enterprise Linux Server (v. 7) | Fixed | RHSA-2020:2381 |
| Red Hat Enterprise Linux Server Optional (v. 6) | Fixed | RHSA-2020:2378, RHSA-2020:2613 |
| Red Hat Enterprise Linux Server Optional (v. 7) | Fixed | RHSA-2020:2381, RHSA-2020:2615 |
| Red Hat Enterprise Linux Workstation (v. 6) | Fixed | RHSA-2020:2378, RHSA-2020:2613 |
| Red Hat Enterprise Linux Workstation (v. 7) | Fixed | RHSA-2020:2381, RHSA-2020:2615 |
| Red Hat Enterprise Linux Workstation Optional (v. 6) | Fixed | RHSA-2020:2378 |
| Red Hat Enterprise Linux Workstation Optional (v. 7) | Fixed | RHSA-2020:2381 |
Timeline
- 2026-10-02 Threatist record created from CVE-2020-12410
- 2026-10-03 Alias added: GHSA-rc5h-67pm-gm2w
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-2020-12410 · CVE Program
- CVE-2020-12410 · NVD
- FIRST EPSS
- GHSA-rc5h-67pm-gm2w · GitHub Advisory Database · CC BY 4.0
- CVE-2020-12410 · 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