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-2011-3268 — Critical (CVSS 10.0): Buffer overflow in the crypt function in PHP before 5.3.7 allows context-dependent attackers to have an unspecified…
• 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-2026-2778 — Critical (CVSS 10.0): Sandbox escape due to incorrect boundary conditions in the DOM: Core & HTML component. This vulnerability was fixed in…
• CVE-2026-2776 — Critical (CVSS 10.0): Sandbox escape due to incorrect boundary conditions in the Telemetry component in External Software. This vulnerability…
• CVE-2025-1866 — Critical (CVSS 10.0): Improper Restriction of Operations within the Bounds of a Memory Buffer vulnerability in warmcat libwebsockets allows…
• CVE-2022-27625 — Critical (CVSS 10.0): A vulnerability regarding improper restriction of operations within the bounds of a memory buffer is found in the…
• CVE-2022-27624 — Critical (CVSS 10.0): A vulnerability regarding improper restriction of operations within the bounds of a memory buffer is found in the…
• CVE-2020-11896 — Critical (CVSS 10.0): The Treck TCP/IP stack before 6.0.1.66 allows Remote Code Execution, related to IPv4 tunneling.

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

Threat intelligence

Threat-intel indicators referencing this CVE:

• 183.182.99.92 (ipv4-addr)
• 103.153.190.105 (ipv4-addr)
• 188.44.20.32 (ipv4-addr)
• 198.199.94.79 (ipv4-addr)
• 122.3.106.113 (ipv4-addr)