High severity · published Oct 28, 2026
CVE-2026-118664
decode-uri-component: Denial of service via quadratic replacement of percent-encoded runs
New
8.2
CVSS
–
EPSS
No
On KEV
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.
Exploitation
Is it being used?
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
DE
decode-uri-component · SamVerschueren
< 0.5.1 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-118664
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-118664
x_refsource_CONFIRM
https://github.com/SamVerschueren/decode-uri-component/security/advisories/GHSA-qr28-fpjm-wq7f
x_refsource_MISC
https://github.com/SamVerschueren/decode-uri-component/commit/fad01d65b93bd3f2f0dc32dfd8d57a38b57bc608
x_refsource_MISC
https://github.com/SamVerschueren/decode-uri-component/releases/tag/v0.5.1
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