CVE-2015-8394 [Critical] | Integer Overflow in Perl Compatible Regular E…

CVE-2015-8394 is rated High Risk (73.9/100): CVSS Critical severity, with high exploitation likelihood (EPSS 4.81%, 91th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. EPSS rose +2.93% over the last day, indicating growing attacker interest. High exploitation likelihood—assess exposure and prioritize remediation.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-15	1.88%	4.81%	+2.93%
2	2026-03-23	3.25%	1.88%	-1.37%
3	2026-03-10	—	3.25%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-06-15

1.88%

4.81%

+2.93%

2026-03-23

3.25%

1.88%

-1.37%

2026-03-10

—

3.25%

—

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]

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]

OS Trackers for CVE-2015-8394

vendor	priority	summary	link
`debian`	not yet assigned	CVE-2015-8394 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-2015-8394
`gentoo`	normal	CVE-2015-8394: 1 GLSA(s) (201607-02), 1 atom(s) (dev-libs/libpcre); latest impact normal.	https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2015-8394
`redhat`	—	—	https://access.redhat.com/security/cve/CVE-2015-8394
`suse`	critical	CVE-2015-8394 severity critical: SUSE including 35 source package names (0.9.1:libpcre1-8.39-7.1, 1.0.0:libpcre1-8.39-7.1, …), 156 product×package rows across 69 product lines (Container caasp/v4/default-http-backend, Container caasp/v4/dnsmasq-nanny, … (69 product lines)): Fixed 105, Known Not Affected 51.	https://www.suse.com/security/cve/CVE-2015-8394/
`ubuntu`	low	CVE-2015-8394 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 7, DNE 4, released 4, ignored 1.	https://ubuntu.com/security/CVE-2015-8394

Affected software / configurations for CVE-2015-8394

Vendor	Product	Version	Raw CPE
pcre	perl_compatible_regular_expression_library	<= 8.37	cpe:2.3:a:pcre:perl_compatible_regular_expression_library::::::::
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-2015-8394

URL	Tags
http://lists.fedoraproject.org/pipermail/package-announce/2016-January/174931.html	Mailing List Third Party Advisory
http://vcs.pcre.org/pcre/code/trunk/ChangeLog?view=markup	Broken Link
http://www.openwall.com/lists/oss-security/2015/11/29/1	Mailing List Third Party Advisory
http://www.securityfocus.com/bid/82990	Third Party Advisory VDB Entry
https://bto.bluecoat.com/security-advisory/sa128	Permissions Required 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/

URL

CVE-2015-8394

Exploit prediction scoring system (EPSS) score for CVE-2015-8394

Common vulnerability scoring system (CVSS) metrics for CVE-2015-8394

Weakness enumeration for CVE-2015-8394

OS Trackers for CVE-2015-8394

Affected software / configurations for CVE-2015-8394

References for CVE-2015-8394