How severe is CVE-2018-17855?

CVE-2018-17855 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2018-17855 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (77th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-17855?

CVE-2018-17855 affects Joomla Joomla!. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2018-17855?

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

When was CVE-2018-17855 published?

CVE-2018-17855 was published on 2018-10-09 and last updated on 2026-06-17.

CVE-2018-17855

CVE-2018-17855 is a high-severity vulnerability in Joomla Joomla! with a CVSS 3.x base score of 8.8. 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-269.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v2: 6.5
EPSS exploit prediction: 2% (77th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-269
Affected product: Joomla Joomla!
Published: 2018-10-09
Last modified: 2026-06-17

Description

An issue was discovered in Joomla! before 3.8.13. If an attacker gets access to the mail account of an user who can approve admin verifications in the registration process, he can activate himself.

Frequently asked questions

What is CVE-2018-17855?: An issue was discovered in Joomla! before 3.8.13. If an attacker gets access to the mail account of an user who can approve admin verifications in the registration process, he can activate himself.
How severe is CVE-2018-17855?: CVE-2018-17855 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2018-17855 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (77th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-17855?: CVE-2018-17855 affects Joomla Joomla!. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2018-17855?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2018-17855 published?: CVE-2018-17855 was published on 2018-10-09 and last updated on 2026-06-17.

References

Affected products (1)

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

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