How severe is CVE-2018-19396?

CVE-2018-19396 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-2018-19396 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 5% (90th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-19396?

CVE-2018-19396 affects Php. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2018-19396?

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-2018-19396 published?

CVE-2018-19396 was published on 2018-11-20 and last updated on 2026-06-17.

CVE-2018-19396

CVE-2018-19396 is a high-severity vulnerability in Php 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-502.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 5% (90th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-502
Affected product: Php
Published: 2018-11-20
Last modified: 2026-06-17

Description

ext/standard/var_unserializer.c in PHP 5.x through 7.1.24 allows attackers to cause a denial of service (application crash) via an unserialize call for the com, dotnet, or variant class.

Frequently asked questions

What is CVE-2018-19396?: ext/standard/var_unserializer.c in PHP 5.x through 7.1.24 allows attackers to cause a denial of service (application crash) via an unserialize call for the com, dotnet, or variant class.
How severe is CVE-2018-19396?: CVE-2018-19396 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-2018-19396 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 5% (90th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-19396?: CVE-2018-19396 affects Php. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2018-19396?: 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-2018-19396 published?: CVE-2018-19396 was published on 2018-11-20 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:php:php:*:*:*:*:*:*:*:*

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Browse all CWE-502 (Deserialization of Untrusted Data) vulnerabilities →

Threat intelligence

Threat-intel indicators referencing this CVE:

45.84.120.3 (ipv4-addr)
79.137.34.248 (ipv4-addr)
221.161.235.168 (ipv4-addr)
200.196.50.91 (ipv4-addr)
187.51.208.158 (ipv4-addr)
187.141.71.166 (ipv4-addr)
187.110.238.50 (ipv4-addr)
182.93.50.90 (ipv4-addr)