GitHub Advisoryadvisory · PyPI

GHSA-7wc8-wvc4-m498 Microdot has HTTP response splitting in Response.set_cookie()

LOW Published 2026-05-05 Modified 2026-05-13 Official page ↗
Aliases
CVE-2026-42874
Ecosystem
PyPI
Packages
microdot
Severity
Low
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
Weaknesses
CWE-113
Reviewed
2026-05-05

Affected packages

• PyPI microdot: < 2.6.1 → fixed in 2.6.1

Description

Impact 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. Patches Upgrade to version 2.6.1. Workarounds Do not pass untrusted data to the `Response.set_cookie()` method.

Related

Alias · CVE (1)

  • CVE-2026-42874 Microdot is a minimalistic Python web framework. vulnerability

Weakness · CWE (1)

  • CWE-113 Improper Neutralization of CRLF Sequences in HTTP Headers weakness

References