Vulnerability · Published Sep 18, 2026 · Assigned by VulnCheck
CVE-2026-93751uri-js through 4.4.1 Improper UTF-8 Decoding via pctDecChars
Medium 6.5
In plain English
A medium-severity security flaw in uri-js from garycourt. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 34% of all known vulnerabilities).
Severity (CVSS 3.1)6.5Medium
Exploit odds (30 days)0.4%top 65.6% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | node-uri-js | no fix listed | DEBIAN-CVE-2026-93751 |
| Debian:13 | node-uri-js | no fix listed | DEBIAN-CVE-2026-93751 |
| Debian:14 | node-uri-js | no fix listed | DEBIAN-CVE-2026-93751 |
| Ubuntu:22.04:LTS | node-uri-js | no fix listed | UBUNTU-CVE-2026-93751 |
| Ubuntu:24.04:LTS | node-uri-js | no fix listed | UBUNTU-CVE-2026-93751 |
| Ubuntu:26.04:LTS | node-uri-js | no fix listed | UBUNTU-CVE-2026-93751 |
| Ubuntu:26.10 | node-uri-js | no fix listed | UBUNTU-CVE-2026-93751 |
Affected products (as reported)
Weakness: CWE-176 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
References
- GitHub Issue #106 issue-tracking
- https://github.com/garycourt/uri-js product
- pctDecChars() masking bytes without continuation-byte validation technical-description
- VulnCheck Advisory: uri-js through 4.4.1 Improper UTF-8 Decoding via pctDecChars third-party-advisory