CVE-2015-2326

Exp

The pcre_compile2 function in PCRE before 8.37 allows context-dependent attackers to compile incorrect code and cause a denial of service (out-of-bounds read) via regular expression with a group containing both a forward referencing subroutine call and a recursive back reference, as demonstrated by "((?+1)(\1))/".

Published: 2020-01-14 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2015-2326 is rated High Exploit Risk (63.4/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 1.59%). 1 public exploit reference(s) are indexed (Exploit-DB). EPSS rose +1.00% over the last day, indicating growing attacker interest. Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

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

Public exploit references (Exploit-DB) for CVE-2015-2326

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2015-2326

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 0.59% 1.59% +1.00%
2 2025-12-28 0.37% 0.59% +0.22%
3 2025-12-27 — 0.37% —

Full EPSS history (10 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2015-2326

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.5 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
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:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 3.6 [email protected]
4.3 2.0 MEDIUM
AV:N/AC:M/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 8.6 2.9 [email protected]

Weakness enumeration for CVE-2015-2326

OS Trackers for CVE-2015-2326

vendor priority summary link
alpine medium CVE-2015-2326: 1 source package rows (pcre); 5 state rows across 5 repos (3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 0, open 5. https://security.alpinelinux.org/vuln/CVE-2015-2326
debian not yet assigned CVE-2015-2326 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-2015-2326
redhat medium — https://access.redhat.com/security/cve/CVE-2015-2326
suse medium — https://www.suse.com/security/cve/CVE-2015-2326/
ubuntu low CVE-2015-2326 low priority: Ubuntu including 1 source packages (pcre3), 7 status rows across 7 suites (lucid, precise, trusty, upstream, utopic, vivid, wily): released 3, ignored 2, needed 1, not-affected 1. https://ubuntu.com/security/CVE-2015-2326

Affected software / configurations for CVE-2015-2326

Vendor Product Version Raw CPE
pcre pcre < 8.37 cpe:2.3:a:pcre:pcre:*:*:*:*:*:*:*:*
opensuse opensuse 13.1 cpe:2.3:o:opensuse:opensuse:13.1:*:*:*:*:*:*:*
opensuse opensuse 13.2 cpe:2.3:o:opensuse:opensuse:13.2:*:*:*:*:*:*:*
mariadb mariadb >= 10.0.0, < 10.0.18 cpe:2.3:a:mariadb:mariadb:*:*:*:*:*:*:*:*
php php >= 5.4.0, < 5.4.41 cpe:2.3:a:php:php:*:*:*:*:*:*:*:*
php php >= 5.5.0, < 5.5.26 cpe:2.3:a:php:php:*:*:*:*:*:*:*:*
php php >= 5.6.0, < 5.6.9 cpe:2.3:a:php:php:*:*:*:*:*:*:*:*

References for CVE-2015-2326

URL Tags
http://lists.opensuse.org/opensuse-updates/2015-05/msg00014.html Mailing List Third Party Advisory
https://bugs.exim.org/show_bug.cgi?id=1592 Exploit Issue Tracking Permissions Required Third Party Advisory
https://fortiguard.com/zeroday/FG-VD-15-016 Third Party Advisory
https://www.pcre.org/original/changelog.txt Release Notes Third Party Advisory
cvelogic Threat Intelligence