fast-uri vulnerable to server-side request forgery via repeated hostname percent-decoding

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 0.0022, the 12th percentile, on 5 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 2 Sept 2026. New records show when each source confirmed them.

Sources

• GitHub Advisory Database: GHSA-fph4-wmhf-6fwf
• OSV: GHSA-fph4-wmhf-6fwf
• github.com/fastify/fast-uri/security/advisories/GHSA-fph4-wmhf-6fwf
• nvd.nist.gov/vuln/detail/CVE-2026-75899
• github.com/fastify/fast-uri/commit/2642290672e7211c990aaed3749c2ce667d0af4f
• github.com/fastify/fast-uri/commit/8c15dbe94ec50bb8e595791ebb42c35cef0fd304
• github.com/fastify/fast-uri/commit/ae92a4c5d8c4b6c9e447f048d5fcbde7eebd5514
• cna.openjsf.org/security-advisories.html
• github.com/fastify/fast-uri
• github.com/fastify/fast-uri/releases/tag/v2.4.5
• github.com/fastify/fast-uri/releases/tag/v3.1.6
• github.com/fastify/fast-uri/releases/tag/v4.1.3

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.