CVE-2016-4541

30

FAUCET Score

CVE-2016-4541 is a critical out-of-bounds read vulnerability in the grapheme_strpos function of PHP versions before 5.5.35, 5.6.21, and 7.0.6, affecting various distributions including Fedora and openSUSE. With a CVSS score of 9.8, it allows unauthenticated remote attackers to cause a denial of service and potentially other impacts with low attack complexity. Despite its critical severity, there is no evidence of active exploitation, public exploit code (Metasploit, Nuclei, ExploitDB), or significant community discussion or media coverage.

Impacted Technologies

Vendor	Product	Version(s)	CPE
		24CPE matchmatch criteria	cpe:2.3:o:fedoraproject:fedora:24:::::::*
		<= 5.5.34CPE matchmatch criteria	cpe:2.3:a:php:php::::::::
		5.6.0CPE matchmatch criteria	cpe:2.3:a:php:php:5.6.0:::::::*
		5.6.1CPE matchmatch criteria	cpe:2.3:a:php:php:5.6.1:::::::*
		5.6.2CPE matchmatch criteria	cpe:2.3:a:php:php:5.6.2:::::::*

CVSS Data

CVSS version used by this source: 3.0

9.8CRITICAL

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

Exploitability Score

3.9

Impact Score

5.9

CvssVersion

3.0

Exploit Intelligence

EPSS Score

6.23%

Probability of exploitation in next 30 days

EPSS Percentile

92.8%

Percentile rank of EPSS score among Peer Group

As of 2026-07-26

Model: v2026.06.15

This CVE's current EPSS score of 0.0623 is in the 87th percentile among its peer group of 36,835 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.1 Reddit, 0.3 Bluesky, 0.3 Mastodon, and 2.4 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.3 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (20)

redhatpatch availablevia redhat_api

Product: Red Hat Software Collections for Red Hat Enterprise Linux 6Fixed in: rh-php56-0:2.3-1.el6

redhatpatch availablevia redhat_api

Product: Red Hat Software Collections for Red Hat Enterprise Linux 6Fixed in: rh-php56-php-0:5.6.25-1.el6

redhatpatch availablevia redhat_api

Product: Red Hat Software Collections for Red Hat Enterprise Linux 6Fixed in: rh-php56-php-pear-1:1.9.5-4.el6

redhatpatch availablevia redhat_api

Product: Red Hat Software Collections for Red Hat Enterprise Linux 6.7 EUSFixed in: rh-php56-0:2.3-1.el6

redhatpatch availablevia redhat_api

Product: Red Hat Software Collections for Red Hat Enterprise Linux 6.7 EUSFixed in: rh-php56-php-0:5.6.25-1.el6

redhatpatch availablevia redhat_api

Product: Red Hat Software Collections for Red Hat Enterprise Linux 6.7 EUSFixed in: rh-php56-php-pear-1:1.9.5-4.el6

redhatpatch availablevia redhat_api

Product: Red Hat Software Collections for Red Hat Enterprise Linux 7Fixed in: rh-php56-0:2.3-1.el7

redhatpatch availablevia redhat_api

Product: Red Hat Software Collections for Red Hat Enterprise Linux 7Fixed in: rh-php56-php-0:5.6.25-1.el7

redhatpatch availablevia redhat_api

Product: Red Hat Software Collections for Red Hat Enterprise Linux 7Fixed in: rh-php56-php-pear-1:1.9.5-4.el7

redhatpatch availablevia redhat_api

Product: Red Hat Software Collections for Red Hat Enterprise Linux 7.2 EUSFixed in: rh-php56-0:2.3-1.el7

redhatpatch availablevia redhat_api

Product: Red Hat Software Collections for Red Hat Enterprise Linux 7.2 EUSFixed in: rh-php56-php-0:5.6.25-1.el7

redhatpatch availablevia redhat_api

Product: Red Hat Software Collections for Red Hat Enterprise Linux 7.2 EUSFixed in: rh-php56-php-pear-1:1.9.5-4.el7

redhatpatch availablevia redhat_api

Product: Red Hat Software Collections for Red Hat Enterprise Linux 7.3 EUSFixed in: rh-php56-0:2.3-1.el7

redhatpatch availablevia redhat_api

Product: Red Hat Software Collections for Red Hat Enterprise Linux 7.3 EUSFixed in: rh-php56-php-0:5.6.25-1.el7

redhatpatch availablevia redhat_api

Product: Red Hat Software Collections for Red Hat Enterprise Linux 7.3 EUSFixed in: rh-php56-php-pear-1:1.9.5-4.el7

redhatend of lifevia redhat_api

Product: Red Hat Enterprise Linux 5Fixed in: php53

redhatend of lifevia redhat_api

Product: Red Hat Enterprise Linux 6Fixed in: php

redhatend of lifevia redhat_api

Product: Red Hat Enterprise Linux 7Fixed in: php

redhatend of lifevia redhat_api

Product: Red Hat Software CollectionsFixed in: php54-php

redhatend of lifevia redhat_api

Product: Red Hat Software CollectionsFixed in: php55-php

Vendor Advisories (1)

redhatCVE-2016-4541Low

php: OOB read in grapheme_stripos and grapheme_strpos when negative offset is used

References

lists.fedoraproject.org / pipermail/package-announce/2016-May/183736.html

lists.opensuse.org / opensuse-updates/2016-05/msg00086.html

lists.opensuse.org / opensuse-updates/2016-06/msg00027.html

php.net / ChangeLog-5.php

Patch

php.net / ChangeLog-7.php

Patch

rhn.redhat.com / errata/RHSA-2016-2750.html

bugs.php.net / bug.php

Exploit

h20566.www2.hpe.com / portal/site/hpsc/public/kb/docDisplay

h20566.www2.hpe.com / portal/site/hpsc/public/kb/docDisplay

h20566.www2.hpe.com / portal/site/hpsc/public/kb/docDisplay

security.gentoo.org / glsa/201611-22

debian.org / security/2016/dsa-3602

openwall.com / lists/oss-security/2016/05/05/21

securityfocus.com / bid/90172