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CWE-174

Double Decoding of the Same Data

1 CVEs Avg CVSS 7.5 MITRE
0
CRITICAL
1
HIGH
0
MEDIUM
0
LOW
0
POC
0
KEV

Monthly

CVE-2026-75899 HIGH PATCH This Week

Double-decoding of percent-encoded hostnames in fast-uri (Node.js URI parser) creates a server-side request forgery and host-policy bypass primitive in versions 2.4.1-2.4.4, 3.1.2-3.1.5, and 4.0.0-4.1.2. The library decodes percent escapes once during hostname parsing and again during authority recomposition, so a single normalize or resolve call on a doubly-encoded input can silently resolve to a different network destination - including loopback addresses - than the encoded form represents. Any application layer sitting fast-uri in front of outbound routing guards, redirect allow-lists, or host-policy checks is therefore vulnerable to SSRF. This is an incomplete-fix variant of CVE-2026-6322; no public exploit code or active exploitation (CISA KEV) has been identified at time of analysis.

SSRF Node.js Fast Uri
NVD GitHub
CVSS 3.1
7.5
EPSS
0.4%
EPSS 0% CVSS 7.5
HIGH PATCH This Week

Double-decoding of percent-encoded hostnames in fast-uri (Node.js URI parser) creates a server-side request forgery and host-policy bypass primitive in versions 2.4.1-2.4.4, 3.1.2-3.1.5, and 4.0.0-4.1.2. The library decodes percent escapes once during hostname parsing and again during authority recomposition, so a single normalize or resolve call on a doubly-encoded input can silently resolve to a different network destination - including loopback addresses - than the encoded form represents. Any application layer sitting fast-uri in front of outbound routing guards, redirect allow-lists, or host-policy checks is therefore vulnerable to SSRF. This is an incomplete-fix variant of CVE-2026-6322; no public exploit code or active exploitation (CISA KEV) has been identified at time of analysis.

SSRF Node.js Fast Uri
NVD GitHub

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