How severe is CVE-2020-8264?

CVE-2020-8264 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-2020-8264 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 71% (99th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-8264?

CVE-2020-8264 affects Rubyonrails Rails. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-8264?

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

When was CVE-2020-8264 published?

CVE-2020-8264 was published on 2021-01-06 and last updated on 2026-06-17.

CVE-2020-8264

CVE-2020-8264 is a medium-severity vulnerability in Rubyonrails Rails with a CVSS 3.x base score of 6.1. Its EPSS exploit-prediction score of 71% places it in the 99th percentile, indicating an elevated likelihood of exploitation. 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: 71% (99th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Rubyonrails Rails
Published: 2021-01-06
Last modified: 2026-06-17

Description

In actionpack gem >= 6.0.0, a possible XSS vulnerability exists when an application is running in development mode allowing an attacker to send or embed (in another page) a specially crafted URL which can allow the attacker to execute JavaScript in the context of the local application. This vulnerability is in the Actionable Exceptions middleware.

Frequently asked questions

What is CVE-2020-8264?: In actionpack gem >= 6.0.0, a possible XSS vulnerability exists when an application is running in development mode allowing an attacker to send or embed (in another page) a specially crafted URL which can allow the attacker to execute JavaScript in the context of the local application. This vulnerability is in the Actionable Exceptions middleware.
How severe is CVE-2020-8264?: CVE-2020-8264 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-2020-8264 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 71% (99th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-8264?: CVE-2020-8264 affects Rubyonrails Rails. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-8264?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-8264 published?: CVE-2020-8264 was published on 2021-01-06 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:rubyonrails:rails:*:*:*:*:*:*:*:*

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