CVE-2026-93751

uri-js through 4.4.1 contains an improper UTF-8 decoding vulnerability in pctDecChars() that decodes invalid and overlong percent-encoded sequences into ASCII metacharacters. Attackers can craft percent-encoded payloads to bypass platform decoder validation and inject path traversal or CRLF sequences that downstream consumers process without filtering.

Score

CVSS 4.0 6.9 Medium

Status

Awaiting Analysis - disclosure@vulncheck.com

Published

2026-09-18

Last modified

2026-09-24

Weaknesses

CWE-176

Affected products

• Uri-js (Garycourt)

References

• https://github.com/garycourt/uri-js
• https://github.com/garycourt/uri-js/blob/a1acf730b4bba3f1097c9f52e7d9d3aba8cdcaae/src/uri.ts#L103-L141
• https://github.com/garycourt/uri-js/issues/106
• https://www.vulncheck.com/advisories/uri-js-through-4.4.1-improper-utf-8-decoding-via-pctdecchars