How severe is CVE-2017-16634?

CVE-2017-16634 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2017-16634 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (91st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2017-16634?

CVE-2017-16634 affects Joomla Joomla!. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2017-16634?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2017-16634 published?

CVE-2017-16634 was published on 2017-11-10 and last updated on 2026-06-17.

CVE-2017-16634

CVE-2017-16634 is a critical-severity vulnerability in Joomla Joomla! with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-287.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 4% (91st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-287
Affected product: Joomla Joomla!
Published: 2017-11-10
Last modified: 2026-06-17

Description

In Joomla! before 3.8.2, a bug allowed third parties to bypass a user's 2-factor authentication method.

Frequently asked questions

What is CVE-2017-16634?: In Joomla! before 3.8.2, a bug allowed third parties to bypass a user's 2-factor authentication method.
How severe is CVE-2017-16634?: CVE-2017-16634 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2017-16634 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (91st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2017-16634?: CVE-2017-16634 affects Joomla Joomla!. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2017-16634?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2017-16634 published?: CVE-2017-16634 was published on 2017-11-10 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:joomla:joomla\!:*:*:*:*:*:*:*:*

More vulnerabilities in Joomla Joomla!

CVE-2026-73373 — Critical (CVSS 9.8): Joomla! Core - [20260810] - Unrestricted uploads of SHTML files in Joomla 1.0.0-5.4.7, 6.0.0-6.1.2 - The default list…
CVE-2026-48904 — Critical (CVSS 9.8): An improper access check allows privelege escalation through the com_users group editing webservice endpoint.
CVE-2026-48902 — Critical (CVSS 9.8): The password and username reset features created plain http links for https connections if the "Force SSL" flag wasn't…
CVE-2026-48899 — Critical (CVSS 9.8): An improper access check allows privilege escalation through the com_users batch task.
CVE-2026-48898 — Critical (CVSS 9.8): An improper access check allows privilege escalation through the com_users batch task.
CVE-2026-40383 — Critical (CVSS 9.8): An improper validation of user-supplied input leads to a local file inclusion vulnerability.

All CVEs affecting Joomla Joomla! →

Other CWE-287 (Improper Authentication) vulnerabilities

CVE-2026-101077 — Critical (CVSS 10.0): A flaw has been found in Netcore NR289-GE 1.4.5102. This impacts the function process_request of the component boa_temp…
CVE-2026-100886 — Critical (CVSS 10.0): A vulnerability was identified in Seetong T8108, T8108P, T8116 and T8232 4.6.1.4-build202604241011. The affected…
CVE-2026-77244 — Critical (CVSS 10.0): MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0,…
CVE-2026-94493 — Critical (CVSS 10.0): A vulnerability was detected in Gigatech PDV5701 1.0.31_240305_112640. This issue affects some unknown processing of…
CVE-2026-83099 — Critical (CVSS 10.0): Vulnerability in the Oracle Forms product of Oracle Fusion Middleware (component: Forms Services, C/S, Charmode).…
CVE-2026-83059 — Critical (CVSS 10.0): Vulnerability in the Oracle Internet Directory product of Oracle Fusion Middleware (component: OID LDAP Server).…

Browse all CWE-287 (Improper Authentication) vulnerabilities →