CVE-2016-9893
CVE-2016-9893 is a critical-severity vulnerability in Mozilla Thunderbird with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-119.
Key facts
- Severity: Critical (CVSS 3.x base score 9.8)
- CVSS v2: 7.5
- EPSS exploit prediction: 3% (83rd percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-119
- Affected product: Mozilla Thunderbird
- Published:
- Last modified:
Description
Memory safety bugs were reported in Thunderbird 45.5. Some of these bugs showed evidence of memory corruption and we presume that with enough effort that some of these could be exploited to run arbitrary code. This vulnerability affects Firefox < 50.1, Firefox ESR < 45.6, and Thunderbird < 45.6.
Frequently asked questions
- What is CVE-2016-9893?
- Memory safety bugs were reported in Thunderbird 45.5. Some of these bugs showed evidence of memory corruption and we presume that with enough effort that some of these could be exploited to run arbitrary code. This vulnerability affects Firefox < 50.1, Firefox ESR < 45.6, and Thunderbird < 45.6.
- How severe is CVE-2016-9893?
- CVE-2016-9893 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
- Is CVE-2016-9893 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (83rd percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2016-9893?
- CVE-2016-9893 primarily affects Mozilla Thunderbird. In total, 20 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
- How do I fix CVE-2016-9893?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
- When was CVE-2016-9893 published?
- CVE-2016-9893 was published on 2018-06-11 and last updated on 2026-06-17.
References
- http://rhn.redhat.com/errata/RHSA-2016-2946.html
- http://rhn.redhat.com/errata/RHSA-2016-2973.html
- http://www.securityfocus.com/bid/94885
- http://www.securitytracker.com/id/1037461
- https://bugzilla.mozilla.org/buglist.cgi?bug_id=1319524%2C1298773%2C1299098%2C1309834%2C1312609%2C1313212%2C1317805%2C1312548%2C1315631%2C1287912
- https://security.gentoo.org/glsa/201701-15
- https://www.debian.org/security/2017/dsa-3757
- https://www.mozilla.org/security/advisories/mfsa2016-94/
- https://www.mozilla.org/security/advisories/mfsa2016-95/
- https://www.mozilla.org/security/advisories/mfsa2016-96/
Affected products (20)
- cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux:5.0:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux:6.0:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux_desktop:5.0:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux_desktop:6.0:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux_desktop:7.0:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux_server:5.0:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux_server:6.0:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux_server:7.0:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux_server_aus:7.3:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux_server_aus:7.4:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux_server_eus:7.3:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux_server_eus:7.4:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux_server_eus:7.5:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux_workstation:5.0:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux_workstation:6.0:*:*:*:*:*:*:*
- cpe:2.3:o:redhat:enterprise_linux_workstation:7.0:*:*:*:*:*:*:*
- cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*
- cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
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