CVE-2015-4602

Exp

The __PHP_Incomplete_Class function in ext/standard/incomplete_class.c in PHP before 5.4.40, 5.5.x before 5.5.24, and 5.6.x before 5.6.8 allows remote attackers to cause a denial of service (application crash) or possibly execute arbitrary code via an unexpected data type, related to a "type confusion" issue.

Published: 2016-05-16 Last update: 2026-05-06 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2015-4602 is rated High Exploit Risk (87/100): CVSS Critical severity, with high exploitation likelihood (EPSS 10.47%, 95th percentile). Core evidence: 1 public exploit reference(s) are indexed (Exploit-DB). Mandatory action: 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-2015-4602

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

Exploit prediction scoring system (EPSS) score for CVE-2015-4602

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 11.01% 10.47% -0.54%
2 2026-05-09 12.86% 11.01% -1.85%
3 2026-02-19 12.86%

Full EPSS history (22 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2015-4602

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.0 CRITICAL
CVSS:3.0/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]
10.0 2.0 HIGH
AV:N/AC:L/Au:N/C:C/I:C/A:C 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:C)
Complete confidentiality impact.
Integrity impact (I:C)
Complete integrity impact.
Availability impact (A:C)
Complete availability impact.
10.0 10.0 [email protected]

Weakness enumeration for CVE-2015-4602

OS Trackers for CVE-2015-4602

vendor priority summary link
redhat medium https://access.redhat.com/security/cve/CVE-2015-4602
ubuntu medium CVE-2015-4602 medium priority: Ubuntu including 1 source packages (php5), 5 status rows across 5 suites (precise, trusty, upstream, utopic, vivid): released 5. https://ubuntu.com/security/CVE-2015-4602

NVD evaluator notes for CVE-2015-4602

Comment: <a href="http://cwe.mitre.org/data/definitions/843.html">Access of Resource Using Incompatible Type ('Type Confusion')</a>

Affected software / configurations for CVE-2015-4602

Vendor Product Version Raw CPE
redhat enterprise_linux 6.0 cpe:2.3:o:redhat:enterprise_linux:6.0:*:*:*:*:*:*:*
redhat enterprise_linux 7.0 cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*
php php <= 5.4.39 cpe:2.3:a:php:php:*:*:*:*:*:*:*:*
php php 5.5.0 cpe:2.3:a:php:php:5.5.0:*:*:*:*:*:*:*
php php 5.5.1 cpe:2.3:a:php:php:5.5.1:*:*:*:*:*:*:*
php php 5.5.2 cpe:2.3:a:php:php:5.5.2:*:*:*:*:*:*:*
php php 5.5.3 cpe:2.3:a:php:php:5.5.3:*:*:*:*:*:*:*
php php 5.5.4 cpe:2.3:a:php:php:5.5.4:*:*:*:*:*:*:*
php php 5.5.5 cpe:2.3:a:php:php:5.5.5:*:*:*:*:*:*:*
php php 5.5.6 cpe:2.3:a:php:php:5.5.6:*:*:*:*:*:*:*
php php 5.5.7 cpe:2.3:a:php:php:5.5.7:*:*:*:*:*:*:*
php php 5.5.8 cpe:2.3:a:php:php:5.5.8:*:*:*:*:*:*:*
php php 5.5.9 cpe:2.3:a:php:php:5.5.9:*:*:*:*:*:*:*
php php 5.5.10 cpe:2.3:a:php:php:5.5.10:*:*:*:*:*:*:*
php php 5.5.11 cpe:2.3:a:php:php:5.5.11:*:*:*:*:*:*:*
php php 5.5.12 cpe:2.3:a:php:php:5.5.12:*:*:*:*:*:*:*
php php 5.5.13 cpe:2.3:a:php:php:5.5.13:*:*:*:*:*:*:*
php php 5.5.14 cpe:2.3:a:php:php:5.5.14:*:*:*:*:*:*:*
php php 5.5.15 cpe:2.3:a:php:php:5.5.15:*:*:*:*:*:*:*
php php 5.5.16 cpe:2.3:a:php:php:5.5.16:*:*:*:*:*:*:*
php php 5.5.17 cpe:2.3:a:php:php:5.5.17:*:*:*:*:*:*:*
php php 5.5.18 cpe:2.3:a:php:php:5.5.18:*:*:*:*:*:*:*
php php 5.5.19 cpe:2.3:a:php:php:5.5.19:*:*:*:*:*:*:*
php php 5.5.20 cpe:2.3:a:php:php:5.5.20:*:*:*:*:*:*:*
php php 5.5.21 cpe:2.3:a:php:php:5.5.21:*:*:*:*:*:*:*
php php 5.5.22 cpe:2.3:a:php:php:5.5.22:*:*:*:*:*:*:*
php php 5.5.23 cpe:2.3:a:php:php:5.5.23:*:*:*:*:*:*:*
php php 5.6.0 cpe:2.3:a:php:php:5.6.0:*:*:*:*:*:*:*
php php 5.6.1 cpe:2.3:a:php:php:5.6.1:*:*:*:*:*:*:*
php php 5.6.2 cpe:2.3:a:php:php:5.6.2:*:*:*:*:*:*:*
php php 5.6.3 cpe:2.3:a:php:php:5.6.3:*:*:*:*:*:*:*
php php 5.6.4 cpe:2.3:a:php:php:5.6.4:*:*:*:*:*:*:*
php php 5.6.5 cpe:2.3:a:php:php:5.6.5:*:*:*:*:*:*:*
php php 5.6.6 cpe:2.3:a:php:php:5.6.6:*:*:*:*:*:*:*
php php 5.6.7 cpe:2.3:a:php:php:5.6.7:*:*:*:*:*:*:*
redhat enterprise_linux_desktop 7.0 cpe:2.3:o:redhat:enterprise_linux_desktop:7.0:*:*:*:*:*:*:*
redhat enterprise_linux_hpc_node 7.0 cpe:2.3:o:redhat:enterprise_linux_hpc_node:7.0:*:*:*:*:*:*:*
redhat enterprise_linux_hpc_node_eus 7.1 cpe:2.3:o:redhat:enterprise_linux_hpc_node_eus:7.1:*:*:*:*:*:*:*
redhat enterprise_linux_server 7.0 cpe:2.3:o:redhat:enterprise_linux_server:7.0:*:*:*:*:*:*:*
redhat enterprise_linux_server_eus 7.1 cpe:2.3:o:redhat:enterprise_linux_server_eus:7.1:*:*:*:*:*:*:*
redhat enterprise_linux_workstation 7.0 cpe:2.3:o:redhat:enterprise_linux_workstation:7.0:*:*:*:*:*:*:*

References for CVE-2015-4602

cvelogic Threat Intelligence