CVE-2015-8386

PCRE before 8.38 mishandles the interaction of lookbehind assertions and mutually recursive subpatterns, which allows remote attackers to cause a denial of service (buffer overflow) or possibly have unspecified other impact via a crafted regular expression, as demonstrated by a JavaScript RegExp object encountered by Konqueror.

Published: 2015-12-02 Last update: 2026-05-06 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2015-8386 is rated High Risk (71.4/100): CVSS Critical severity, with high exploitation likelihood (EPSS 7.06%, 93th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2015-8386

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 7.52% 7.06% -0.46%
2 2026-03-23 6.48% 7.52% +1.04%
3 2026-03-10 — 6.48% —

Full EPSS history (22 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2015-8386

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 [email protected]
7.5 2.0 HIGH
AV:N/AC:L/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 6.4 [email protected]

Weakness enumeration for CVE-2015-8386

OS Trackers for CVE-2015-8386

vendor priority summary link
debian not yet assigned CVE-2015-8386 not yet assigned priority: Debian including 1 source packages (pcre3), 2 status rows across 2 suites (bookworm, bullseye): resolved 2. https://security-tracker.debian.org/tracker/CVE-2015-8386
gentoo normal CVE-2015-8386: 1 GLSA(s) (201607-02), 1 atom(s) (dev-libs/libpcre); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2015-8386
redhat low — https://access.redhat.com/security/cve/CVE-2015-8386
suse critical CVE-2015-8386 severity critical: SUSE including 39 source package names (0.9.1:libpcre1-8.39-7.1, 1.0.0:libpcre1-8.39-7.1, …), 160 product×package rows across 70 product lines (Container caasp/v4/default-http-backend, Container caasp/v4/dnsmasq-nanny, … (70 product lines)): Fixed 109, Known Not Affected 51. https://www.suse.com/security/cve/CVE-2015-8386/
ubuntu low CVE-2015-8386 low priority: Ubuntu including 2 source packages (pcre2, pcre3), 16 status rows across 8 suites (precise, trusty, upstream, vivid, wily, xenial, yakkety, zesty): not-affected 8, DNE 4, released 3, ignored 1. https://ubuntu.com/security/CVE-2015-8386

Affected software / configurations for CVE-2015-8386

Vendor Product Version Raw CPE
pcre perl_compatible_regular_expression_library <= 8.37 cpe:2.3:a:pcre:perl_compatible_regular_expression_library:*:*:*:*:*:*:*:*
fedoraproject fedora 22 cpe:2.3:o:fedoraproject:fedora:22:*:*:*:*:*:*:*
oracle linux 7 cpe:2.3:o:oracle:linux:7:*:*:*:*:*:*:*
php php >= 5.5.0, < 5.5.32 cpe:2.3:a:php:php:*:*:*:*:*:*:*:*
php php >= 5.6.0, < 5.6.18 cpe:2.3:a:php:php:*:*:*:*:*:*:*:*
php php >= 7.0.0, < 7.0.3 cpe:2.3:a:php:php:*:*:*:*:*:*:*:*

References for CVE-2015-8386

URL Tags
http://lists.fedoraproject.org/pipermail/package-announce/2016-January/174931.html Third Party Advisory
http://rhn.redhat.com/errata/RHSA-2016-1025.html Third Party Advisory
http://rhn.redhat.com/errata/RHSA-2016-2750.html Third Party Advisory
http://vcs.pcre.org/pcre/code/trunk/ChangeLog?view=markup Broken Link Release Notes
http://www-01.ibm.com/support/docview.wss?uid=isg3T1023886 Third Party Advisory
http://www.openwall.com/lists/oss-security/2015/11/29/1 Mailing List Third Party Advisory
http://www.oracle.com/technetwork/topics/security/linuxbulletinapr2016-2952096.html Third Party Advisory
http://www.securityfocus.com/bid/82990 Third Party Advisory VDB Entry
https://access.redhat.com/errata/RHSA-2016:1132 Third Party Advisory
https://bto.bluecoat.com/security-advisory/sa128 Third Party Advisory
https://h20566.www2.hpe.com/portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c05240731 Third Party Advisory
https://security.gentoo.org/glsa/201607-02 Third Party Advisory
https://security.netapp.com/advisory/ntap-20230216-0002/
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