Integer overflow in Mozilla Firefox
Priority MEDIUM 57CWE-190Published · 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
- Partial Red Hat: 6 without a fix
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-190 and the CVSS impact.
Summary
An integer overflow during the parsing of XML using the Expat library. This vulnerability affects Firefox < 50.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.05363 92nd percentileScored 2026-11-07
Fix Partial Firefox (Mozilla): 50Red Hat: 6 without a fix
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Mozilla | Firefox | before 50 | 50 | Patch available | CNA |
- Firefox VendorMozilla Affected before 50 Fixed in 50 Patch available CNA
CPE configurations NVD · 5
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:* | before 50 | Vulnerable | Mozilla |
| cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:* | 8.0 | Vulnerable | Debian |
| cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* | 9.0 | Vulnerable | Debian |
| cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* | 10.0 | Vulnerable | Debian |
| cpe:2.3:a:python:python:*:*:*:*:*:*:*:* | 2.7.0 to before 2.7.15; 3.3.0 to before 3.3.7; 3.4.0 to before 3.4.7; 3.5.0 to before 3.5.4; 3.6.0 to before 3.6.2 | Vulnerable | python-pillow |
- cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:* Versions before 50 Vulnerable ·Mozilla
- cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:* Versions 8.0 Vulnerable ·Debian
- cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* Versions 9.0 Vulnerable ·Debian
- cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* Versions 10.0 Vulnerable ·Debian
- cpe:2.3:a:python:python:*:*:*:*:*:*:*:* Versions 2.7.0 to before 2.7.15; 3.3.0 to before 3.3.7; 3.4.0 to before 3.4.7; 3.5.0 to before 3.5.4; 3.6.0 to before 3.6.2 Vulnerable ·python-pillow
Remediation
- Fix · CNA Firefox (Mozilla) Fixed in 50
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Release ·
Mozilla Firefox 50
20 records Highest priority Priority MEDIUM 3 MEDIUM, 17 LOW
Other records, highest priority first
- TI-2016-07429 Access control flaw in Mozilla FirefoxPriority MEDIUM 46
- TI-2016-04585 Memory corruption in Mozilla FirefoxPriority MEDIUM 46
- TI-2016-07424 Access control flaw in Mozilla FirefoxPriority LOW 39
Vendor assessments
Red Hat
Red Hat rating: Low. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 5 | Affected | No fix planned: Will not fix |
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Will not fix |
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Will not fix |
| Red Hat Enterprise Virtualization 3 | Affected | No fix planned: Will not fix |
| Red Hat JBoss Enterprise Application Platform 6 | Affected | No fix planned: Will not fix |
| Red Hat JBoss Enterprise Web Server 2 | Affected | No fix planned: Will not fix |
Not affected: 3 products
- Red Hat Enterprise Linux 5
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
Timeline
- 2026-10-02 Threatist record created from CVE-2016-9063
- 2026-10-03 Alias added: GHSA-v3g4-2m5p-cjh4
- 2026-10-08 CISA SSVC decision points changed
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-2016-9063 · CVE Program
- CVE-2016-9063 · NVD
- FIRST EPSS
- GHSA-v3g4-2m5p-cjh4 · GitHub Advisory Database · CC BY 4.0
- CVE-2016-9063 · Red Hat security data · CC BY 4.0
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