CVE-2016-8638

A vulnerability in ipsilon 2.0 before 2.0.2, 1.2 before 1.2.1, 1.1 before 1.1.2, and 1.0 before 1.0.3 was found that allows attacker to log out active sessions of other users. This issue is related to how it tracks sessions, and allows an unauthenticated attacker to view and terminate active sessions from other users. It is also called a "SAML2 multi-session vulnerability."

Published: 2017-07-12 Last update: 2026-05-13 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2016-8638 is rated Moderate Risk (63.1/100): CVSS Critical severity, with high exploitation likelihood (EPSS 7.14%, 91th 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-2016-8638

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 2025-03-30 12.30% 7.14% -5.16%
2 2025-03-29 7.14% 12.30% +5.16%
3 2025-03-17 — 7.14% —

Full EPSS history (11 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2016-8638

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.1 3.0 CRITICAL
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/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: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.
 3.9 5.2 [email protected]
6.4 2.0 MEDIUM
AV:N/AC:L/Au:N/C:P/I:N/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:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 4.9 [email protected]

Weakness enumeration for CVE-2016-8638

GitHub Security Advisory for CVE-2016-8638

OS Trackers for CVE-2016-8638

vendor priority summary link
redhat high — https://access.redhat.com/security/cve/CVE-2016-8638

Affected software / configurations for CVE-2016-8638

Vendor Product Version Raw CPE
ipsilon_project ipsilon 1.0.0 cpe:2.3:a:ipsilon_project:ipsilon:1.0.0:*:*:*:*:*:*:*
ipsilon_project ipsilon 1.0.1 cpe:2.3:a:ipsilon_project:ipsilon:1.0.1:*:*:*:*:*:*:*
ipsilon_project ipsilon 1.0.2 cpe:2.3:a:ipsilon_project:ipsilon:1.0.2:*:*:*:*:*:*:*
ipsilon_project ipsilon 1.1.0 cpe:2.3:a:ipsilon_project:ipsilon:1.1.0:*:*:*:*:*:*:*
ipsilon_project ipsilon 1.1.1 cpe:2.3:a:ipsilon_project:ipsilon:1.1.1:*:*:*:*:*:*:*
ipsilon_project ipsilon 1.2.0 cpe:2.3:a:ipsilon_project:ipsilon:1.2.0:*:*:*:*:*:*:*
ipsilon_project ipsilon 2.0.0 cpe:2.3:a:ipsilon_project:ipsilon:2.0.0:*:*:*:*:*:*:*
ipsilon_project ipsilon 2.0.1 cpe:2.3:a:ipsilon_project:ipsilon:2.0.1:*:*:*:*:*:*:*

References for CVE-2016-8638

cvelogic Threat Intelligence