fast-uri vulnerable to server-side request forgery via malformed IPv6 normalization

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 8 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-f65p-4m7j-42xc
• OSV: GHSA-f65p-4m7j-42xc
• github.com/fastify/fast-uri/security/advisories/GHSA-f65p-4m7j-42xc
• nvd.nist.gov/vuln/detail/CVE-2026-75975
• github.com/fastify/fast-uri/commit/3728465caacef4b16bc84b7d14760f1c8fe41595
• github.com/fastify/fast-uri/commit/607bfbe953f28a14c2e06ae64aff38c81ca2937f
• github.com/fastify/fast-uri/commit/9161eded1ff55fad9d9714c6ad6c0f0283547799
• 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.