Cross-site scripting in actionpack

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

• CISA KEV Not listed.
• EPSS 0.67, the 99th percentile, on 9 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

This record came from the full history of the GitHub Advisory Database, published 7 Apr 2021. New records show when each source confirmed them.

Sources

• GitHub Advisory Database: GHSA-35mm-cc6r-8fjp
• OSV: GHSA-35mm-cc6r-8fjp
• nvd.nist.gov/vuln/detail/CVE-2020-8264
• hackerone.com/reports/904059
• github.com/rubysec/ruby-advisory-db/blob/master/gems/actionpack/CVE-2020-8264.yml
• groups.google.com/g/rubyonrails-security/c/yQzUVfv42jk
• groups.google.com/g/rubyonrails-security/c/yQzUVfv42jk/m/oJWw-xhNAQAJ

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.