Vulnerability Description
Microdot is a minimalistic Python web framework. Prior to 2.6.1, the Response.set_cookie() method does not sanitize its string arguments, and in particular will not detect the presence of the \r\n sequence in them. This can be a potential source of header injection attacks. For a header injection attack through this issue to be possible, an attacker must first infiltrate the client (for example through an independent XSS attack), so that it can send malicious information that is destined to be stored in a cookie by the server on behalf of the victim. An attacker that infiltrates one client can only orchestrate a header injection attack for that client, all other clients that were not infiltrated are safe. This vulnerability is fixed in 2.6.1.
CVSS Score
LOW
Related Weaknesses (CWE)
References
- https://github.com/miguelgrinberg/microdot/blob/main/CHANGES.md
- https://github.com/miguelgrinberg/microdot/commit/99b281b45faef8472410f2d56bfef4
- https://github.com/miguelgrinberg/microdot/security/advisories/GHSA-7wc8-wvc4-m4
FAQ
What is CVE-2026-42874?
CVE-2026-42874 is a vulnerability with a CVSS score of 3.7 (LOW). Microdot is a minimalistic Python web framework. Prior to 2.6.1, the Response.set_cookie() method does not sanitize its string arguments, and in particular will not detect the presence of the \r\n seq...
How severe is CVE-2026-42874?
CVE-2026-42874 has been rated LOW with a CVSS base score of 3.7/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-42874?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.