Crass: Incorrect tokenization of bad URLs enables CSS sanitizer bypass

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 0.0035, the 29th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

1. 27 Oct 2026, 20:10 UTC Confirmed by the CVE List
2. 27 Oct 2026, 21:18 UTC Confirmed by NVD
3. 31 Oct 2026, 14:21 UTC First seen by agentprime
4. 31 Oct 2026, 14:21 UTC Confirmed by OSV

Sources

• GitHub Advisory Database: GHSA-pq4g-8rxf-4g29
• OSV: GHSA-pq4g-8rxf-4g29
• github.com/rgrove/crass/security/advisories/GHSA-pq4g-8rxf-4g29
• nvd.nist.gov/vuln/detail/CVE-2026-116695
• github.com/rgrove/crass/commit/689fc45c632fdf3803b2f4e844ffc9cca3b08f34
• github.com/rgrove/crass
• github.com/rgrove/crass/releases/tag/v1.0.8
• github.com/rubysec/ruby-advisory-db/blob/master/gems/crass/GHSA-pq4g-8rxf-4g29.yml

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.