How severe is CVE-2016-5311?

CVE-2016-5311 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2016-5311 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (49th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2016-5311?

CVE-2016-5311 primarily affects Symantec Endpoint Protection. In total, 9 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2016-5311?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2016-5311 published?

CVE-2016-5311 was published on 2020-01-09 and last updated on 2026-06-17.

CVE-2016-5311

CVE-2016-5311 is a high-severity vulnerability in Symantec Endpoint Protection with a CVSS 3.x base score of 7.8. 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-427.

Key facts

Severity: High (CVSS 3.x base score 7.8)
CVSS v2: 6.9
EPSS exploit prediction: 1% (49th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-427
Affected product: Symantec Endpoint Protection
Published: 2020-01-09
Last modified: 2026-06-17

Description

A Privilege Escalation vulnerability exists in Symantec Norton Antivirus, Norton AntiVirus with Backup, Norton Security, Norton Security with Backup, Norton Internet Security, Norton 360, Endpoint Protection Small Business Edition Cloud, and Endpoint Protection Cloud Client due to a DLL-preloading without path restrictions, which could let a local malicious user obtain system privileges.

Frequently asked questions

What is CVE-2016-5311?: A Privilege Escalation vulnerability exists in Symantec Norton Antivirus, Norton AntiVirus with Backup, Norton Security, Norton Security with Backup, Norton Internet Security, Norton 360, Endpoint Protection Small Business Edition Cloud, and Endpoint Protection Cloud Client due to a DLL-preloading without path restrictions, which could let a local malicious user obtain system privileges.
How severe is CVE-2016-5311?: CVE-2016-5311 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2016-5311 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (49th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2016-5311?: CVE-2016-5311 primarily affects Symantec Endpoint Protection. In total, 9 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2016-5311?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2016-5311 published?: CVE-2016-5311 was published on 2020-01-09 and last updated on 2026-06-17.

References

Affected products (9)

cpe:2.3:a:symantec:endpoint_protection:*:*:*:*:*:*:*:*
cpe:2.3:a:symantec:endpoint_protection_cloud:*:*:*:*:*:*:*:*
cpe:2.3:a:symantec:norton_360:*:*:*:*:*:*:*:*
cpe:2.3:a:symantec:norton_antivirus:*:*:*:*:*:*:*:*
cpe:2.3:a:symantec:norton_antivirus_with_backup:*:*:*:*:*:*:*:*
cpe:2.3:a:symantec:norton_family:*:*:*:*:*:*:*:*
cpe:2.3:a:symantec:norton_internet_security:*:*:*:*:*:*:*:*
cpe:2.3:a:symantec:norton_security:*:*:*:*:*:*:*:*
cpe:2.3:a:symantec:norton_security_with_backup:*:*:*:*:*:*:*:*

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Other CWE-427 (Uncontrolled Search Path Element) vulnerabilities

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CVE-2023-53959 — Critical (CVSS 9.8): FileZilla Client 3.63.1 contains a DLL hijacking vulnerability that allows attackers to execute malicious code by…
CVE-2025-65741 — Critical (CVSS 9.8): Sublime Text 3 Build 3208 or prior for MacOS is vulnerable to Dylib Injection. An attacker could compile a .dylib file…
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