CVE-2016-4073

CVE-2016-4073 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-119.

Key facts

• Severity: Critical (CVSS 3.x base score 9.8)
• CVSS v2: 7.5
• EPSS exploit prediction: 7% (94th percentile)
• Actively exploited: Not listed in CISA KEV
• Weakness: CWE-119
• Affected product: Php
• Published: 2016-05-20
• Last modified: 2026-06-17

Description

Multiple integer overflows in the mbfl_strcut function in ext/mbstring/libmbfl/mbfl/mbfilter.c in PHP before 5.5.34, 5.6.x before 5.6.20, and 7.x before 7.0.5 allow remote attackers to cause a denial of service (application crash) or possibly execute arbitrary code via a crafted mb_strcut call.

Frequently asked questions

What is CVE-2016-4073?

Multiple integer overflows in the mbfl_strcut function in ext/mbstring/libmbfl/mbfl/mbfilter.c in PHP before 5.5.34, 5.6.x before 5.6.20, and 7.x before 7.0.5 allow remote attackers to cause a denial of service (application crash) or possibly execute arbitrary code via a crafted mb_strcut call.

How severe is CVE-2016-4073?

CVE-2016-4073 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-2016-4073 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 7% (94th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2016-4073?

CVE-2016-4073 primarily affects Php. In total, 76 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2016-4073?

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-2016-4073 published?

CVE-2016-4073 was published on 2016-05-20 and last updated on 2026-06-17.

References

• http://lists.apple.com/archives/security-announce/2016/May/msg00004.html
• http://lists.opensuse.org/opensuse-security-announce/2016-05/msg00031.html
• http://lists.opensuse.org/opensuse-security-announce/2016-05/msg00033.html
• http://lists.opensuse.org/opensuse-security-announce/2016-05/msg00056.html
• http://rhn.redhat.com/errata/RHSA-2016-2750.html
• http://www.debian.org/security/2016/dsa-3560
• http://www.openwall.com/lists/oss-security/2016/04/24/1
• http://www.php.net/ChangeLog-5.php
• http://www.php.net/ChangeLog-7.php
• http://www.securityfocus.com/bid/85991
• http://www.ubuntu.com/usn/USN-2952-1
• http://www.ubuntu.com/usn/USN-2952-2
• https://bugs.php.net/bug.php?id=71906
• https://gist.github.com/smalyshev/d8355c96a657cc5dba70
• https://git.php.net/?p=php-src.git%3Ba=commit%3Bh=64f42c73efc58e88671ad76b6b6bc8e2b62713e1
• https://h20566.www2.hpe.com/portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c05240731
• https://security.gentoo.org/glsa/201611-22
• https://support.apple.com/HT206567

Affected products (76)

• cpe:2.3:a:php:php:5.5.0:*:*:*:*:*:*:*
• cpe:2.3:a:php:php:5.5.0:alpha1:*:*:*:*:*:*
• cpe:2.3:a:php:php:5.5.0:alpha2:*:*:*:*:*:*
• cpe:2.3:a:php:php:5.5.0:alpha3:*:*:*:*:*:*
• cpe:2.3:a:php:php:5.5.0:alpha4:*:*:*:*:*:*
• cpe:2.3:a:php:php:5.5.0:alpha5:*:*:*:*:*:*
• cpe:2.3:a:php:php:5.5.0:alpha6:*:*:*:*:*:*
• cpe:2.3:a:php:php:5.5.0:beta1:*:*:*:*:*:*
• cpe:2.3:a:php:php:5.5.0:beta2:*:*:*:*:*:*
• cpe:2.3:a:php:php:5.5.0:beta3:*:*:*:*:*:*
• cpe:2.3:a:php:php:5.5.0:beta4:*:*:*:*:*:*
• cpe:2.3:a:php:php:5.5.0:rc1:*:*:*:*:*:*
• cpe:2.3:a:php:php:5.5.0:rc2:*:*:*:*:*:*
• cpe:2.3:a:php:php:5.5.1:*:*:*:*:*:*:*
• cpe:2.3:a:php:php:5.5.2:*:*:*:*:*:*:*
• cpe:2.3:a:php:php:5.5.3:*:*:*:*:*:*:*
• cpe:2.3:a:php:php:5.5.4:*:*:*:*:*:*:*
• cpe:2.3:a:php:php:5.5.5:*:*:*:*:*:*:*
• cpe:2.3:a:php:php:5.5.6:*:*:*:*:*:*:*
• cpe:2.3:a:php:php:5.5.7:*:*:*:*:*:*:*
• cpe:2.3:a:php:php:5.5.8:*:*:*:*:*:*:*
• cpe:2.3:a:php:php:5.5.9:*:*:*:*:*:*:*
• cpe:2.3:a:php:php:5.5.10:*:*:*:*:*:*:*
• cpe:2.3:a:php:php:5.5.11:*:*:*:*:*:*:*
• cpe:2.3:a:php:php:5.5.12:*:*:*:*:*:*:*
• cpe:2.3:a:php:php:5.5.13:*:*:*:*:*:*:*
• cpe:2.3:a:php:php:5.5.14:*:*:*:*:*:*:*
• cpe:2.3:a:php:php:5.5.18:*:*:*:*:*:*:*
• cpe:2.3:a:php:php:5.5.19:*:*:*:*:*:*:*
• cpe:2.3:a:php:php:5.5.20:*:*:*:*:*:*:*
• cpe:2.3:a:php:php:5.5.21:*:*:*:*:*:*:*
• cpe:2.3:a:php:php:5.5.22:*:*:*:*:*:*:*
• cpe:2.3:a:php:php:5.5.23:*:*:*:*:*:*:*
• cpe:2.3:a:php:php:5.5.24:*:*:*:*:*:*:*
• cpe:2.3:a:php:php:5.5.25:*:*:*:*:*:*:*
• cpe:2.3:a:php:php:5.5.26:*:*:*:*:*:*:*
• cpe:2.3:a:php:php:5.5.27:*:*:*:*:*:*:*
• cpe:2.3:a:php:php:5.5.29:*:*:*:*:*:*:*
• cpe:2.3:a:php:php:5.5.30:*:*:*:*:*:*:*
• cpe:2.3:a:php:php:5.5.32:*:*:*:*:*:*:*

More vulnerabilities in Php

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• CVE-2012-2376 — Critical (CVSS 10.0): Buffer overflow in the com_print_typeinfo function in PHP 5.4.3 and earlier on Windows allows remote attackers to…
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• CVE-2009-4143 — Critical (CVSS 10.0): PHP before 5.2.12 does not properly handle session data, which has unspecified impact and attack vectors related to (1)…
• CVE-2008-5557 — Critical (CVSS 10.0): Heap-based buffer overflow in ext/mbstring/libmbfl/filters/mbfilter_htmlent.c in the mbstring extension in PHP 4.3.0…

All CVEs affecting Php →

Other CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer) vulnerabilities

• CVE-2026-105285 — Critical (CVSS 10.0): A security vulnerability has been detected in Totolink A3002MU 1.0.0-B20230403.1455. This affects an unknown function…
• CVE-2026-104610 — Critical (CVSS 10.0): A security vulnerability has been detected in Tenda HG7, HG9 and HG10 300001138_en_xpon. This impacts the function…
• CVE-2026-101039 — Critical (CVSS 10.0): A vulnerability was identified in FAST FAC1900R 20190827_2.0.2. Affected by this issue is the function copy_msg_element…
• CVE-2026-96257 — Critical (CVSS 10.0): A flaw has been found in Fast FAC1203R Gigabit Edition 2.0.4. Affected by this issue is the function copy_msg_element…
• CVE-2026-94089 — Critical (CVSS 10.0): A vulnerability was determined in D-Link DIR-868L 2.01b05. This issue affects the function strcpy of the file…
• CVE-2026-94003 — Critical (CVSS 10.0): A vulnerability has been found in Comfast CF-N1-S 2.6.0.1. Impacted is the function get_css_path_from_uri of the file…

Browse all CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer) vulnerabilities →

Threat intelligence

Threat-intel indicators referencing this CVE:

• 103.153.190.105 (ipv4-addr)
• 47.95.205.253 (ipv4-addr)
• 183.182.99.92 (ipv4-addr)
• 47.95.197.30 (ipv4-addr)
• 121.196.222.241 (ipv4-addr)
• 47.95.211.126 (ipv4-addr)
• 121.43.145.58 (ipv4-addr)
• 121.41.165.15 (ipv4-addr)