CVE-2016-4540

Severity: critical (CVSS 9.8 v3.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 6.1% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2016-05-22 · updated 2026-06-17

Description

The grapheme_stripos function in ext/intl/grapheme/grapheme_string.c in PHP before 5.5.35, 5.6.x before 5.6.21, and 7.x before 7.0.6 allows remote attackers to cause a denial of service (out-of-bounds read) or possibly have unspecified other impact via a negative offset.

Affected products

Fedoraproject Fedora: 24
openSUSE Leap: 42.1
PHP: through 5.5.34; 5.6.0, 5.6.1, 5.6.2, 5.6.3, 5.6.4, 5.6.5 (+21)

References

http://lists.fedoraproject.org/pipermail/package-announce/2016-May/183736.html
http://lists.opensuse.org/opensuse-updates/2016-05/msg00086.html
http://lists.opensuse.org/opensuse-updates/2016-06/msg00027.html
http://php.net/ChangeLog-5.php
http://php.net/ChangeLog-7.php
http://rhn.redhat.com/errata/RHSA-2016-2750.html
http://www.debian.org/security/2016/dsa-3602
http://www.openwall.com/lists/oss-security/2016/05/05/21
http://www.securityfocus.com/bid/90172
https://bugs.php.net/bug.php?id=72061
https://git.php.net/?p=php-src.git%3Ba=commit%3Bh=fd9689745c44341b1bd6af4756f324be8abba2fb
https://h20566.www2.hpe.com/portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c05240731

Get alerted when CVE-2016-4540 or the next vulnerability affects your stack