How severe is CVE-2016-5391?

CVE-2016-5391 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2016-5391 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (86th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2016-5391?

CVE-2016-5391 primarily affects Libreswan. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2016-5391?

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-2016-5391 published?

CVE-2016-5391 was published on 2017-06-13 and last updated on 2026-06-17.

CVE-2016-5391

CVE-2016-5391 is a high-severity vulnerability in Libreswan with a CVSS 3.x base score of 7.5. 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-476.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 3% (86th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-476
Affected product: Libreswan
Published: 2017-06-13
Last modified: 2026-06-17

Description

libreswan before 3.18 allows remote attackers to cause a denial of service (NULL pointer dereference and pluto daemon restart).

Frequently asked questions

What is CVE-2016-5391?: libreswan before 3.18 allows remote attackers to cause a denial of service (NULL pointer dereference and pluto daemon restart).
How severe is CVE-2016-5391?: CVE-2016-5391 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2016-5391 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (86th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2016-5391?: CVE-2016-5391 primarily affects Libreswan. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2016-5391?: 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-2016-5391 published?: CVE-2016-5391 was published on 2017-06-13 and last updated on 2026-06-17.

References

Affected products (3)

cpe:2.3:a:libreswan:libreswan:*:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:23:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:24:*:*:*:*:*:*:*

More vulnerabilities in Libreswan

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Browse all CWE-476 (NULL Pointer Dereference) vulnerabilities →