How severe is CVE-2016-5386?

CVE-2016-5386 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2016-5386 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 5% (92nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2016-5386?

CVE-2016-5386 primarily affects Redhat Enterprise Linux Server. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2016-5386?

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-2016-5386 published?

CVE-2016-5386 was published on 2016-07-19 and last updated on 2026-06-17.

CVE-2016-5386

CVE-2016-5386 is a high-severity vulnerability in Redhat Enterprise Linux Server with a CVSS 3.x base score of 8.1. 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-284.

Key facts

Severity: High (CVSS 3.x base score 8.1)
CVSS v2: 6.8
EPSS exploit prediction: 5% (92nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-284
Affected product: Redhat Enterprise Linux Server
Published: 2016-07-19
Last modified: 2026-06-17

Description

The net/http package in Go through 1.6 does not attempt to address RFC 3875 section 4.1.18 namespace conflicts and therefore does not protect CGI applications from the presence of untrusted client data in the HTTP_PROXY environment variable, which might allow remote attackers to redirect a CGI application's outbound HTTP traffic to an arbitrary proxy server via a crafted Proxy header in an HTTP request, aka an "httpoxy" issue.

Frequently asked questions

What is CVE-2016-5386?: The net/http package in Go through 1.6 does not attempt to address RFC 3875 section 4.1.18 namespace conflicts and therefore does not protect CGI applications from the presence of untrusted client data in the HTTP_PROXY environment variable, which might allow remote attackers to redirect a CGI application's outbound HTTP traffic to an arbitrary proxy server via a crafted Proxy header in an HTTP request, aka an "httpoxy" issue.
How severe is CVE-2016-5386?: CVE-2016-5386 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2016-5386 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 5% (92nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2016-5386?: CVE-2016-5386 primarily affects Redhat Enterprise Linux Server. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2016-5386?: 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-2016-5386 published?: CVE-2016-5386 was published on 2016-07-19 and last updated on 2026-06-17.

References

Affected products (8)

cpe:2.3:o:fedoraproject:fedora:23:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:24:*:*:*:*:*:*:*
cpe:2.3:o:oracle:linux:7:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_server:7.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_server_aus:7.2:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_server_eus:7.2:*:*:*:*:*:*:*
cpe:2.3:a:golang:go:*:*:*:*:*:*:*:*
cpe:2.3:a:golang:go:1.7:rc1:*:*:*:*:*:*

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