CVE-2015-8866

Name: CVE-2015-8866
Creator: NVD / NIST
Published: 2016-05-22T01:59:05.727+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.6/10EPSS 4.03%

Last modified Jun 17, 2026

CVE-2015-8866 is a critical-severity vulnerability rated 9.6/10 on the CVSS scale. ext/libxml/libxml.c in PHP before 5.5.22 and 5.6.x before 5.6.6, when PHP-FPM is used, does not isolate each thread from libxml_disable_entity_loader changes in other threads, which allows remote attackers to conduct XML External Entity (XXE) and XML Entity Expansion (XEE) attacks via a crafted XML document, a related issue to CVE-2015-5161.. EPSS estimates a 4.03% chance of exploitation in the next 30 days.

Description

ext/libxml/libxml.c in PHP before 5.5.22 and 5.6.x before 5.6.6, when PHP-FPM is used, does not isolate each thread from libxml_disable_entity_loader changes in other threads, which allows remote attackers to conduct XML External Entity (XXE) and XML Entity Expansion (XEE) attacks via a crafted XML document, a related issue to CVE-2015-5161.

Metrics

CVSS 3.1

9.6/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

EPSS Probability

4.03%

89.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-611

Affected Software

Vendor	Product	Versions
Php	Php	>= 5.5.0, < 5.5.22
Php	Php	>= 5.6.0, < 5.6.6
Php	Php	>= 7.0.0, < 7.0.27
Php	Php	>= 7.1.0, < 7.1.13
Php	Php	>= 7.2.0, < 7.2.1
Canonical	Ubuntu Linux	12.04
Canonical	Ubuntu Linux	14.04
Canonical	Ubuntu Linux	15.10
Opensuse	Leap	42.1
Opensuse	Opensuse	13.2
Suse	Linux Enterprise Module For Web Scripting	12
Suse	Linux Enterprise Software Development Kit	12

References

http://git.php.net/?p=php-src.git%3Ba=commit%3Bh=de31324c221c1791b26350ba106cc26bad23ace9
http://lists.opensuse.org/opensuse-security-announce/2016-05/msg00031.htmlMailing List, Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2016-05/msg00033.htmlMailing List, Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2016-05/msg00056.htmlMailing List, Third Party Advisory
http://rhn.redhat.com/errata/RHSA-2016-2750.htmlThird Party Advisory
http://www.openwall.com/lists/oss-security/2016/04/24/1Mailing List, Patch, Third Party Advisory
http://www.php.net/ChangeLog-5.phpRelease Notes, Vendor Advisory
http://www.securityfocus.com/bid/87470Third Party Advisory, VDB Entry
http://www.ubuntu.com/usn/USN-2952-1Third Party Advisory
http://www.ubuntu.com/usn/USN-2952-2Third Party Advisory
https://bugs.launchpad.net/ubuntu/+source/php5/+bug/1509817Issue Tracking, Patch, Third Party Advisory
https://bugs.php.net/bug.php?id=64938Exploit, Issue Tracking, Patch, Vendor Advisory
http://git.php.net/?p=php-src.git%3Ba=commit%3Bh=de31324c221c1791b26350ba106cc26bad23ace9
http://lists.opensuse.org/opensuse-security-announce/2016-05/msg00031.htmlMailing List, Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2016-05/msg00033.htmlMailing List, Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2016-05/msg00056.htmlMailing List, Third Party Advisory
http://rhn.redhat.com/errata/RHSA-2016-2750.htmlThird Party Advisory
http://www.openwall.com/lists/oss-security/2016/04/24/1Mailing List, Patch, Third Party Advisory
http://www.php.net/ChangeLog-5.phpRelease Notes, Vendor Advisory
http://www.securityfocus.com/bid/87470Third Party Advisory, VDB Entry
http://www.ubuntu.com/usn/USN-2952-1Third Party Advisory
http://www.ubuntu.com/usn/USN-2952-2Third Party Advisory
https://bugs.launchpad.net/ubuntu/+source/php5/+bug/1509817Issue Tracking, Patch, Third Party Advisory
https://bugs.php.net/bug.php?id=64938Exploit, Issue Tracking, Patch, Vendor Advisory

Timeline

Published: May 22, 2016
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2015-8866?

How severe is CVE-2015-8866?

CVE-2015-8866 has a CVSS score of 9.6/10 (CRITICAL severity). The EPSS model estimates a 4.03% probability of exploitation in the next 30 days.

How do I fix CVE-2015-8866?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2015-8866?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST