cvedb.io
CVE-2021-39185
CRITICAL · CVSS 9.1
EPSS exploitation probability: 0%
Published 2021-09-01T20:15:07.447 · Last modified 2026-06-17T04:03:16.257

Summary

Http4s is a minimal, idiomatic Scala interface for HTTP services. In http4s versions 0.21.26 and prior, 0.22.0 through 0.22.2, 0.23.0, 0.23.1, and 1.0.0-M1 through 1.0.0-M24, the default CORS configuration is vulnerable to an origin reflection attack. The middleware is also susceptible to a Null Origin Attack. The problem is fixed in 0.21.27, 0.22.3, 0.23.2, and 1.0.0-M25. The original `CORS` implementation and `CORSConfig` are deprecated. See the GitHub GHSA for more information, including code examples and workarounds.

Affected products

typelevel — http4s

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.