CVE-2015-8394

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 4.8% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2015-12-02 · updated 2026-06-17
Weakness: CWE-190

Description

PCRE before 8.38 mishandles the (?(<digits>) and (?(R<digits>) conditions, which allows remote attackers to cause a denial of service (integer overflow) or possibly have unspecified other impact via a crafted regular expression, as demonstrated by a JavaScript RegExp object encountered by Konqueror.

Affected products

PCRE Perl Compatible Regular Expression Library: through 8.37
PHP: from 5.5.0 before 5.5.32; from 5.6.0 before 5.6.18; from 7.0.0 before 7.0.3 — fixed in 5.5.32, 5.6.18, 7.0.3

How to fix

Upgrade to a fixed version: PHP 5.5.32, 5.6.18, 7.0.3. Check the vendor advisory for mitigations.

References

http://lists.fedoraproject.org/pipermail/package-announce/2016-January/174931.html
http://vcs.pcre.org/pcre/code/trunk/ChangeLog?view=markup
http://www.openwall.com/lists/oss-security/2015/11/29/1
http://www.securityfocus.com/bid/82990
https://bto.bluecoat.com/security-advisory/sa128
https://h20566.www2.hpe.com/portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c05240731
https://security.gentoo.org/glsa/201607-02
https://security.netapp.com/advisory/ntap-20230216-0002/
http://lists.fedoraproject.org/pipermail/package-announce/2016-January/174931.html
http://vcs.pcre.org/pcre/code/trunk/ChangeLog?view=markup
http://www.openwall.com/lists/oss-security/2015/11/29/1
http://www.securityfocus.com/bid/82990

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