What’s Vulnerable › Vulnerabilities

CVE-2015-6837

• Severity: high (CVSS 7.5 v3.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 7.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2016-05-16 · updated 2026-06-17

Description

The xsl_ext_function_php function in ext/xsl/xsltprocessor.c in PHP before 5.4.45, 5.5.x before 5.5.29, and 5.6.x before 5.6.13, when libxml2 before 2.9.2 is used, does not consider the possibility of a NULL valuePop return value before proceeding with a free operation during initial error checking, which allows remote attackers to cause a denial of service (NULL pointer dereference and application crash) via a crafted XML document, a different vulnerability than CVE-2015-6838.

Affected products

• PHP: through 5.4.44; 5.6.0-alpha1, 5.6.0-alpha2, 5.6.0-alpha3, 5.6.0-alpha4, 5.6.0-alpha5, 5.6.0-beta1 (+56)
• xmlsoft libxml2: through 2.9.1

References

• http://php.net/ChangeLog-5.php
• http://www.debian.org/security/2015/dsa-3358
• http://www.securityfocus.com/bid/76738
• http://www.securitytracker.com/id/1033548
• https://bugs.php.net/bug.php?id=69782
• https://security.gentoo.org/glsa/201606-10
• http://php.net/ChangeLog-5.php
• http://www.debian.org/security/2015/dsa-3358
• http://www.securityfocus.com/bid/76738
• http://www.securitytracker.com/id/1033548
• https://bugs.php.net/bug.php?id=69782
• https://security.gentoo.org/glsa/201606-10

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