How severe is CVE-2016-4344?

CVE-2016-4344 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2016-4344 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 5% (91st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2016-4344?

CVE-2016-4344 affects Php. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2016-4344?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2016-4344 published?

CVE-2016-4344 was published on 2016-05-22 and last updated on 2026-06-17.

CVE-2016-4344

CVE-2016-4344 is a critical-severity vulnerability in Php with a CVSS 3.x base score of 9.8. 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-190.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 5% (91st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-190
Affected product: Php
Published: 2016-05-22
Last modified: 2026-06-17

Description

Integer overflow in the xml_utf8_encode function in ext/xml/xml.c in PHP before 7.0.4 allows remote attackers to cause a denial of service or possibly have unspecified other impact via a long argument to the utf8_encode function, leading to a heap-based buffer overflow.

Frequently asked questions

What is CVE-2016-4344?: Integer overflow in the xml_utf8_encode function in ext/xml/xml.c in PHP before 7.0.4 allows remote attackers to cause a denial of service or possibly have unspecified other impact via a long argument to the utf8_encode function, leading to a heap-based buffer overflow.
How severe is CVE-2016-4344?: CVE-2016-4344 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2016-4344 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 5% (91st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2016-4344?: CVE-2016-4344 affects Php. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2016-4344?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2016-4344 published?: CVE-2016-4344 was published on 2016-05-22 and last updated on 2026-06-17.

References

Affected products (1)

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

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