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No exploitation reportedFix available

CVE-2015-6838

No exploitation reported by the sources we read.

  • Published2016-05-16

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

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 after the principal argument loop, 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-2015-6837.

Timeline

dates in UTC
  1. 2016-05-1610:59CVE publishedNVD

Versions per branch

NVD
PHP
BranchAffectedFixed in
5.6= 5.6.0no fix published
5.6= 5.6.1no fix published
5.6= 5.6.2no fix published
5.6= 5.6.3no fix published
5.6= 5.6.4no fix published
5.6= 5.6.5no fix published
5.6= 5.6.6no fix published
5.6= 5.6.7no fix published
5.6= 5.6.8no fix published
5.6= 5.6.9no fix published
5.6= 5.6.10no fix published
5.6= 5.6.11no fix published
Xmlsoft libxml2
BranchAffectedFixed in
2.9≤ 2.9.1no fix published

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

  • phpTuxCare:CentOS:6all versions · fixed in 5.3.3-51.el6.cloudlinuxand 26 other packages
  • phpMageia:4all versions · fixed in 5.5.29-1.mga4
  • php-apcMageia:4all versions · fixed in 3.1.15-4.19.mga4
  • php5Ubuntu:14.04:LTSall versions · fixed in 5.5.9+dfsg-1ubuntu4.13
  • php5SUSE:Linux Enterprise Software Development Kit 12all versions · fixed in 5.5.14-36.1
  • php5SUSE:Linux Enterprise Server 11 SP2-LTSSall versions · fixed in 5.2.14-0.7.30.72.1
  • php5SUSE:Linux Enterprise Module for Web and Scripting 12all versions · fixed in 5.5.14-36.1
  • php5Debian:8all versions · fixed in 5.6.13+dfsg-0+deb8u1

12 more package ranges on OSV.dev

Vendor advisories

  • RHSA-2016:0457 Red Hat Product Security240 products fixed

    Red Hat Security Advisory: rh-php56-php security update

Full record on NVD

Fix

  1. Vendor fix Red Hat Product Security RHSA-2016:0457 · 240 productsBefore applying this update, make sure all previously released errata relevant to your system have been applied. For details on how to apply this update, refer to: https://access.redhat.com/articles/11258

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof of concept
Metasploit modules
none listed
Metasploit Framework

Sources

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published
2016-05-16
Last Modified
2026-06-17
NVD status
Modified
GitHub Advisory
GHSA-q5x2-3h44-rh43

Frequently asked questions

What is CVE-2015-6838?

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 after the principal argument loop, 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-2015-6837.

Is CVE-2015-6838 actively exploited?

Active exploitation of CVE-2015-6838 has not been confirmed. Its EPSS score was 8.1% on 2026-11-09, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2015-6838?

CVE-2015-6838 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

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