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critical 9.6

CVE-2015-8866 in the critical feed json

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_ent…

published 10y ago modified 4mo ago also EUVD-2015-8722

cvss
9.6
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
4.2%
EPSS 4.2% chance of exploitation in 30 days, percentile 90%
public exploits
0
none known

Summary

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.

Patch / fix

  • php php 5.5.22, 5.6.6, 7.0.27, 7.1.13, 7.2.1
  • php5 Ubuntu 14.04 LTS 5.5.9+dfsg-1ubuntu4.16

ubuntu advisories UBUNTU-CVE-2015-8866

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • rh-php56 RHEL 2 SOFTWARE_COLLECTIONS 2.3-1.el6
  • rh-php56 RHEL 2 SOFTWARE_COLLECTIONS 2.3-1.el7
  • rh-php56-php RHEL 2 SOFTWARE_COLLECTIONS 5.6.25-1.el6
  • rh-php56-php RHEL 2 SOFTWARE_COLLECTIONS 5.6.25-1.el7
  • rh-php56-php-gd RHEL 2 SOFTWARE_COLLECTIONS 5.6.25-1.el6
  • rh-php56-php-gd RHEL 2 SOFTWARE_COLLECTIONS 5.6.25-1.el7
  • rh-php56-php-cli RHEL 2 SOFTWARE_COLLECTIONS 5.6.25-1.el6
  • rh-php56-php-cli RHEL 2 SOFTWARE_COLLECTIONS 5.6.25-1.el7

red hat advisories RHSA-2016:2750

  • php53 SLES for SAP 11 SP4, SLES 11 SP4, SLES 11 SP3-TERADATA +5 more 5.3.17-71.1
  • php53 SLES for SAP 11 SP4, SLES 11 SP4, SLE Software Development Kit 11 SP4 5.3.17-62.1
  • php5 SLE Software Development Kit 12 SP1, SLE Software Development Kit 12, SLE Module for Web and Scripting 12 5.5.14-56.1
  • php53 SLES 11 SP2-LTSS 5.3.17-47.1

suse advisories SUSE-SU-2016:1638-1SUSE-SU-2016:1581-1SUSE-SU-2016:1310-1SUSE-SU-2016:1277-1

Is CVE-2015-8866 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2015-8866 updated cvss 3.7

php: libxml_disable_entity_loader setting is shared between threads

  • Red Hat Enterprise Linux 5 php, php53 Red Hat Enterprise Linux 6 php, php-gd, php-cli, php-dba, php-fpm, php-pdo, +20 more Red Hat Enterprise Linux 7 php, php-gd, php-cli, php-dba, php-fpm, php-pdo, +18 more Red Hat Software Collections php54-php, php55-php, php54-php-gd, php55-php-gd, php54-php-cli, php54-php-dba, +44 more
    affected: no fix planned “Will not fix”
  • Red Hat Software Collections for Red Hat Enterprise Linux Server (v. 6) rh-php56 2.3-1.el6, rh-php56-php 5.6.25-1.el6, rh-php56-runtime 2.3-1.el6, rh-php56-scldevel 2.3-1.el6, rh-php56-php-gd 5.6.25-1.el6, rh-php56-php-cli 5.6.25-1.el6, +26 more Red Hat Software Collections for Red Hat Enterprise Linux Server (v. 7) rh-php56 2.3-1.el7, rh-php56-php 5.6.25-1.el7, rh-php56-runtime 2.3-1.el7, rh-php56-scldevel 2.3-1.el7, rh-php56-php-gd 5.6.25-1.el7, rh-php56-php-cli 5.6.25-1.el7, +24 more Red Hat Software Collections for Red Hat Enterprise Linux Server EUS (v. 6.7) rh-php56 2.3-1.el6, rh-php56-php 5.6.25-1.el6, rh-php56-runtime 2.3-1.el6, rh-php56-scldevel 2.3-1.el6, rh-php56-php-gd 5.6.25-1.el6, rh-php56-php-cli 5.6.25-1.el6, +26 more Red Hat Software Collections for Red Hat Enterprise Linux Server EUS (v. 7.2) rh-php56 2.3-1.el7, rh-php56-php 5.6.25-1.el7, rh-php56-runtime 2.3-1.el7, rh-php56-scldevel 2.3-1.el7, rh-php56-php-gd 5.6.25-1.el7, rh-php56-php-cli 5.6.25-1.el7, +24 more Red Hat Software Collections for Red Hat Enterprise Linux Server EUS (v. 7.3) rh-php56 2.3-1.el7, rh-php56-php 5.6.25-1.el7, rh-php56-runtime 2.3-1.el7, rh-php56-scldevel 2.3-1.el7, rh-php56-php-gd 5.6.25-1.el7, rh-php56-php-cli 5.6.25-1.el7, +24 more Red Hat Software Collections for Red Hat Enterprise Linux Workstation (v. 6) rh-php56 2.3-1.el6, rh-php56-php 5.6.25-1.el6, rh-php56-runtime 2.3-1.el6, rh-php56-scldevel 2.3-1.el6, rh-php56-php-gd 5.6.25-1.el6, rh-php56-php-cli 5.6.25-1.el6, +26 more
    +1 more products
    Red Hat Software Collections for Red Hat Enterprise Linux Workstation (v. 7) rh-php56 2.3-1.el7, rh-php56-php 5.6.25-1.el7, rh-php56-runtime 2.3-1.el7, rh-php56-scldevel 2.3-1.el7, rh-php56-php-gd 5.6.25-1.el7, rh-php56-php-cli 5.6.25-1.el7, +24 more
    fixed: vendor fix RHSA-2016:2750

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

4.17% chance of exploitation in the next 30 days, higher than 90% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • bugs.php.net https://bugs.php.net/bug.php?id=64938 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 9.6 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
NVD 2.0 6.8 AV:N/AC:M/Au:N/C:P/I:P/A:P

Classification

Weakness
  • CWE-611 Improper Restriction of XML External Entity Reference
Technology feeds

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.