CVE-2026-118664 decode-uri-component: Denial of service via quadratic replacement of percent-encoded runs
- Exploited in the wild
- Not known
- Fix
- Available
What is CVE-2026-118664?
CVE-2026-118664 is a high-severity vulnerability in SamVerschueren decode-uri-component, published on 28 Oct 2026.
Official description
decode-uri-component provides a more robust alternative to decodeURIComponent. Prior to 0.5.1, decodeUriComponent in index.js falls back to customDecodeURIComponent after native decoding throws, and the fallback collects every distinct percent-encoded run before performing a full-string regular-expression replacement for each entry. Malformed input containing many distinct runs can therefore make both the number of replacements and the scanned input length grow together, causing quadratic CPU consumption and blocking the Node.js event loop; request-body inputs can reach the demonstrated size, while ordinary URL header limits reduce the practical delay. This issue is fixed in version 0.5.1.
Which versions are affected by CVE-2026-118664?
2 open source packages ship an affected version, including decode-uri-component.
| Package | Affected | Fixed in |
|---|---|---|
decode-uri-component npm | All versions | 0.5.1 |
decode-uri-component npm | All versions | 0.5.1 |
How do I fix CVE-2026-118664?
Upgrade decode-uri-component to 0.5.1 or later.
Is CVE-2026-118664 being exploited?
There is no known exploitation of CVE-2026-118664 in the wild and no public exploit code.
Sources
Also known as GHSA-qr28-fpjm-wq7f.