Koa is expressive middleware for Node.js using ES2017 async functions. In koa < 2.16.1 and < 3.0.0-alpha.5, passing untrusted user input to ctx.redirect() even after sanitizing it, may execute javascript code on the user who use the app. This issue is patched in 2.16.1 and 3.0.0-alpha.5.
CVE ID: CVE-2025-32379
CVSS Base Severity: MEDIUM
CVSS Base Score: 5.0
CVSS Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:L
Vendor: koajs
Product: koa
EPSS Score: 0.04% (probability of being exploited)
EPSS Percentile: 9.38% (scored less or equal to compared to others)
EPSS Date: 2025-04-21 (when was this score calculated)