Findings

CVE-2026-42874

Microdot is a minimalistic Python web framework.

Published May 11, 2026 · updated Jun 17, 2026

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.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. May 11, 2026 · NIST NVD

    Detected

    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 th

  2. Jun 17, 2026 · NIST NVD

    Updated

    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 th

Sources

  • CVE.orgVulnerability recordCVE-2026-42874

    Official CVE identifier

    cve.org
  • NIST NVDVulnerability recordCVE-2026-42874

    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

    nvd.nist.gov

References