XSS in Koajs Koa

CVE-2025-32379

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.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.0 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:L.

EPSS exploit prediction

EPSS: 0.003 (15.7th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 16th percentile — 15.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-32379: held from 0.002 to 0.003.

EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.000

Affected products

  • Koajs Koa — versions >= 3.0.0-alpha.0, < 3.0.0-alpha.5, 3.0.0, < 2.16.1

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-32379?
CVE-2025-32379 is a medium-severity vulnerability in Koajs Koa, classified under Cross-site Scripting. CVSS score: 5.0/10. Published 2025-04-09.
How severe is CVE-2025-32379?
Medium severity. CVSS v3 base score is 5.0 out of 10.
Is CVE-2025-32379 known to be exploited?
2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.