How severe is CVE-2018-11627?

CVE-2018-11627 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2018-11627 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (80th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-11627?

CVE-2018-11627 primarily affects Sinatrarb Sinatra. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2018-11627?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2018-11627 published?

CVE-2018-11627 was published on 2018-05-31 and last updated on 2026-06-17.

CVE-2018-11627

CVE-2018-11627 is a medium-severity vulnerability in Sinatrarb Sinatra with a CVSS 3.x base score of 6.1. 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-79.

Key facts

Severity: Medium (CVSS 3.x base score 6.1)
CVSS v2: 4.3
EPSS exploit prediction: 2% (80th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Sinatrarb Sinatra
Published: 2018-05-31
Last modified: 2026-06-17

Description

Sinatra before 2.0.2 has XSS via the 400 Bad Request page that occurs upon a params parser exception.

Frequently asked questions

What is CVE-2018-11627?: Sinatra before 2.0.2 has XSS via the 400 Bad Request page that occurs upon a params parser exception.
How severe is CVE-2018-11627?: CVE-2018-11627 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2018-11627 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (80th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-11627?: CVE-2018-11627 primarily affects Sinatrarb Sinatra. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2018-11627?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2018-11627 published?: CVE-2018-11627 was published on 2018-05-31 and last updated on 2026-06-17.

References

Affected products (3)

cpe:2.3:a:sinatrarb:sinatra:*:*:*:*:*:*:*:*
cpe:2.3:a:redhat:cloudforms:4.6:*:*:*:*:*:*:*
cpe:2.3:a:redhat:cloudforms:4.7:*:*:*:*:*:*:*

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