Buffer overflow in Mozilla Firefox
Priority MEDIUM 41CWE-120Published · 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: 14 fixed, 1 without a fix
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-120 and the CVSS impact.
Summary
An attacker could have caused 4 bytes of HMAC output to be written past the end of a buffer stored on the stack. This could be used by an attacker to execute arbitrary code or more likely lead to a crash. This vulnerability affects Firefox < 70, Thunderbird < 68.2, and Firefox ESR < 68.2.
Why it matters now
EPSS 0.01646 76th percentileScored 2026-11-07
Fix Partial Firefox (Mozilla): 70Thunderbird (Mozilla): 68.2+1 more productRed Hat: 6 advisoriesRed Hat: 14 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 | Firefox | before 70 | 70 | Patch available | CNA |
| Mozilla | Thunderbird | before 68.2 | 68.2 | Patch available | CNA |
| Mozilla | Firefox ESR | before 68.2 | 68.2 | Patch available | CNA |
- Firefox VendorMozilla Affected before 70 Fixed in 70 Patch available CNA
- Thunderbird VendorMozilla Affected before 68.2 Fixed in 68.2 Patch available CNA
- Firefox ESR VendorMozilla Affected before 68.2 Fixed in 68.2 Patch available CNA
CPE configurations NVD · 4
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:* | before 70.0 | Vulnerable | Mozilla |
| cpe:2.3:a:mozilla:firefox_esr:*:*:*:*:*:*:*:* | before 68.2 | Vulnerable | Mozilla |
| cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:* | before 68.2 | Vulnerable | Mozilla |
| cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:esm:*:*:* | 16.04 | Vulnerable | Canonical |
- cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:* Versions before 70.0 Vulnerable ·Mozilla
- cpe:2.3:a:mozilla:firefox_esr:*:*:*:*:*:*:*:* Versions before 68.2 Vulnerable ·Mozilla
- cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:* Versions before 68.2 Vulnerable ·Mozilla
- cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:esm:*:*:* Versions 16.04 Vulnerable ·Canonical
Remediation
- Fix · CNA Firefox (Mozilla) Fixed in 70
- Fix · CNA Thunderbird (Mozilla) Fixed in 68.2
- Fix · CNA Firefox ESR (Mozilla) Fixed in 68.2
Red Hat 6 advisories
- RHSA-2019:3756 Released 2019-11-06 · Red Hat rating Importantthunderbird security update
- Red Hat Enterprise Linux Desktop (v. 6) thunderbird-68.2.0-2.el6_10
- Red Hat Enterprise Linux Server Optional (v. 6) thunderbird-68.2.0-2.el6_10
- Red Hat Enterprise Linux Workstation (v. 6) thunderbird-68.2.0-2.el6_10
- RHSA-2019:3281 Released 2019-10-31 · Red Hat rating Criticalfirefox security update
- Red Hat Enterprise Linux Desktop (v. 6) firefox-68.2.0-4.el6_10
- Red Hat Enterprise Linux Desktop Optional (v. 6) firefox-68.2.0-4.el6_10
- Red Hat Enterprise Linux HPC Node Optional (v. 6) firefox-68.2.0-4.el6_10
- Red Hat Enterprise Linux Server (v. 6) firefox-68.2.0-4.el6_10
- Red Hat Enterprise Linux Server Optional (v. 6) firefox-68.2.0-4.el6_10
- Red Hat Enterprise Linux Workstation (v. 6) firefox-68.2.0-4.el6_10
- Red Hat Enterprise Linux Workstation Optional (v. 6) firefox-68.2.0-4.el6_10
- RHSA-2019:3237 Released 2019-10-29 · Red Hat rating Importantthunderbird security update
- Red Hat Enterprise Linux AppStream (v. 8) thunderbird-68.2.0-1.el8_0
Show 3 more Red Hat advisories
- RHSA-2019:3210 Released 2019-10-29 · Red Hat rating Importantthunderbird security update
- Red Hat Enterprise Linux Client (v. 7) thunderbird-68.2.0-1.el7_7
- Red Hat Enterprise Linux Server Optional (v. 7) thunderbird-68.2.0-1.el7_7
- Red Hat Enterprise Linux Workstation (v. 7) thunderbird-68.2.0-1.el7_7
- RHSA-2019:3193 Released 2019-10-24 · Red Hat rating Criticalfirefox security update
- Red Hat Enterprise Linux Client (v. 7) firefox-68.2.0-1.el7_7
- Red Hat Enterprise Linux Client Optional (v. 7) firefox-68.2.0-1.el7_7
- Red Hat Enterprise Linux Server (v. 7) firefox-68.2.0-1.el7_7
- Red Hat Enterprise Linux Server Optional (v. 7) firefox-68.2.0-1.el7_7
- Red Hat Enterprise Linux Workstation (v. 7) firefox-68.2.0-1.el7_7
- Red Hat Enterprise Linux Workstation Optional (v. 7) firefox-68.2.0-1.el7_7
- RHSA-2019:3196 Released 2019-10-24 · Red Hat rating Criticalfirefox security update
- Red Hat Enterprise Linux AppStream (v. 8) firefox-68.2.0-2.el8_0
Vendor assessments
Red Hat
Red Hat rating: Moderate. 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-2019:3196, RHSA-2019:3237 |
| Red Hat Enterprise Linux Client (v. 7) | Fixed | RHSA-2019:3193, RHSA-2019:3210 |
| Red Hat Enterprise Linux Client Optional (v. 7) | Fixed | RHSA-2019:3193 |
| Red Hat Enterprise Linux Desktop (v. 6) | Fixed | RHSA-2019:3281, RHSA-2019:3756 |
| Red Hat Enterprise Linux Desktop Optional (v. 6) | Fixed | RHSA-2019:3281 |
| Red Hat Enterprise Linux HPC Node Optional (v. 6) | Fixed | RHSA-2019:3281 |
| Red Hat Enterprise Linux Server (v. 6) | Fixed | RHSA-2019:3281 |
| Red Hat Enterprise Linux Server (v. 7) | Fixed | RHSA-2019:3193 |
| Red Hat Enterprise Linux Server Optional (v. 6) | Fixed | RHSA-2019:3281, RHSA-2019:3756 |
| Red Hat Enterprise Linux Server Optional (v. 7) | Fixed | RHSA-2019:3193, RHSA-2019:3210 |
| Red Hat Enterprise Linux Workstation (v. 6) | Fixed | RHSA-2019:3281, RHSA-2019:3756 |
| Red Hat Enterprise Linux Workstation (v. 7) | Fixed | RHSA-2019:3193, RHSA-2019:3210 |
| Red Hat Enterprise Linux Workstation Optional (v. 6) | Fixed | RHSA-2019:3281 |
| Red Hat Enterprise Linux Workstation Optional (v. 7) | Fixed | RHSA-2019:3193 |
Timeline
- 2026-10-02 Threatist record created from CVE-2019-11759
- 2026-10-03 Alias added: GHSA-2h74-w2gg-96g2
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-2019-11759 · CVE Program
- CVE-2019-11759 · NVD
- FIRST EPSS
- GHSA-2h74-w2gg-96g2 · GitHub Advisory Database · CC BY 4.0
- CVE-2019-11759 · 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