How severe is CVE-2019-5599?

CVE-2019-5599 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-2019-5599 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-2019-5599?

CVE-2019-5599 primarily affects Freebsd. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2019-5599?

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-2019-5599 published?

CVE-2019-5599 was published on 2019-07-02 and last updated on 2026-06-17.

CVE-2019-5599

CVE-2019-5599 is a high-severity vulnerability in Freebsd 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-770.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 7.8
EPSS exploit prediction: 5% (92nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-770
Affected product: Freebsd
Published: 2019-07-02
Last modified: 2026-06-17

Description

In FreeBSD 12.0-STABLE before r349197 and 12.0-RELEASE before 12.0-RELEASE-p6, a bug in the non-default RACK TCP stack can allow an attacker to cause several linked lists to grow unbounded and cause an expensive list traversal on every packet being processed, leading to resource exhaustion and a denial of service.

Frequently asked questions

What is CVE-2019-5599?: In FreeBSD 12.0-STABLE before r349197 and 12.0-RELEASE before 12.0-RELEASE-p6, a bug in the non-default RACK TCP stack can allow an attacker to cause several linked lists to grow unbounded and cause an expensive list traversal on every packet being processed, leading to resource exhaustion and a denial of service.
How severe is CVE-2019-5599?: CVE-2019-5599 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-2019-5599 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-2019-5599?: CVE-2019-5599 primarily affects Freebsd. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2019-5599?: 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-2019-5599 published?: CVE-2019-5599 was published on 2019-07-02 and last updated on 2026-06-17.

References

Affected products (6)

cpe:2.3:o:freebsd:freebsd:12.0:-:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:12.0:p1:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:12.0:p2:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:12.0:p3:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:12.0:p4:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:12.0:p5:*:*:*:*:*:*

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