Rack Gem Subject to Denial of Service via Hash Collisions

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

No source has published a CVSS score for this record yet.

• CISA KEV Not listed.
• EPSS 0.039, the 90th percentile, on 8 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

1. 31 Oct 2026, 15:12 UTC First seen by agentprime
2. 31 Oct 2026, 15:12 UTC Confirmed by OSV

Sources

• GitHub Advisory Database: GHSA-v6j3-7jrw-hq2p
• OSV: GHSA-v6j3-7jrw-hq2p
• nvd.nist.gov/vuln/detail/CVE-2011-5036
• gist.github.com/52bbc6b9cc19ce330829
• github.com/rubysec/ruby-advisory-db/blob/master/gems/rack/CVE-2011-5036.yml
• web.archive.org/web/20120201040317/http://jruby.org/2011/12/27/jruby-1-6-5-1
• web.archive.org/web/20130213132312/http://archives.neohapsis.com/archives/bugtraq/2011-12/0181.html
• www.debian.org/security/2013/dsa-2783
• www.kb.cert.org/vuls/id/903934
• www.nruns.com/_downloads/advisory28122011.pdf
• www.ocert.org/advisories/ocert-2011-003.html

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.