There is a MEDIUM severity vulnerability affecting CPython.

When using http.cookies.Morsel, user-controlled cookie values and parameters can allow injecting HTTP headers into messages. Patch rejects all control characters within cookie names, values, and parameters.

Please see the linked CVE ID for the latest information on affected versions:

• https://www.cve.org/CVERecord?id=CVE-2026-0672
• https://github.com/python/cpython/pull/143920