fast-uri vulnerable to host confusion via unchecked WHATWG host canonicalization

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 0.0026, the 17th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

1. 31 Oct 2026, 13:33 UTC First seen by agentprime
2. 31 Oct 2026, 13:33 UTC Confirmed by OSV

Sources

• GitHub Advisory Database: GHSA-wjr9-j795-jxcr
• OSV: GHSA-wjr9-j795-jxcr
• github.com/fastify/fast-uri/security/advisories/GHSA-wjr9-j795-jxcr
• nvd.nist.gov/vuln/detail/CVE-2026-110180
• github.com/fastify/fast-uri/commit/58c183d0b168ad87f98773266444ce1f6375803a
• github.com/fastify/fast-uri/commit/ddfc6a51122dfce0365655f04479fc3adb7f6b3c
• github.com/fastify/fast-uri/commit/f6d46dfeab025d0c440485f4ae29fa4f14707646
• cna.openjsf.org/security-advisories.html
• github.com/fastify/fast-uri
• github.com/fastify/fast-uri/releases/tag/v2.4.8
• github.com/fastify/fast-uri/releases/tag/v3.1.9
• github.com/fastify/fast-uri/releases/tag/v4.2.3

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.