How severe is CVE-2018-18956?

CVE-2018-18956 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-2018-18956 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (85th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-18956?

CVE-2018-18956 affects Suricata-ids Suricata. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2018-18956?

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-2018-18956 published?

CVE-2018-18956 was published on 2018-11-05 and last updated on 2026-06-17.

CVE-2018-18956

CVE-2018-18956 is a high-severity vulnerability in Suricata-ids Suricata 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-119.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 3% (85th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-119
Affected product: Suricata-ids Suricata
Published: 2018-11-05
Last modified: 2026-06-17

Description

The ProcessMimeEntity function in util-decode-mime.c in Suricata 4.x before 4.0.6 allows remote attackers to cause a denial of service (segfault and daemon crash) via crafted input to the SMTP parser, as exploited in the wild in November 2018.

Frequently asked questions

What is CVE-2018-18956?: The ProcessMimeEntity function in util-decode-mime.c in Suricata 4.x before 4.0.6 allows remote attackers to cause a denial of service (segfault and daemon crash) via crafted input to the SMTP parser, as exploited in the wild in November 2018.
How severe is CVE-2018-18956?: CVE-2018-18956 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-2018-18956 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (85th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-18956?: CVE-2018-18956 affects Suricata-ids Suricata. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2018-18956?: 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-2018-18956 published?: CVE-2018-18956 was published on 2018-11-05 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:suricata-ids:suricata:*:*:*:*:*:*:*:*

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