PT-2026-59296 · Pypi · Microdot

Published 2026-07-13 · Updated 2026-07-13

OSV

CVSS v3.1

3.7

Low

Base vector

AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N

Impact

The Response.set cookie() method does not sanitize its string arguments, and in particular will not detect the presence of the r 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.

Fix

Related Identifiers

PYSEC-2026-2646

Affected Products

Microdot

References · 8

• https://nvd.nist.gov/vuln/detail/CVE-2026-42874 · Security Note
• https://osv.dev/vulnerability/PYSEC-2026-2646 · Vendor Advisory
• https://github.com/miguelgrinberg/microdot · Note
• https://github.com/miguelgrinberg/microdot/blob/main/CHANGES.md · Note
• https://github.com/miguelgrinberg/microdot/commit/99b281b45faef8472410f2d56bfef496dfbd95d5 · Note
• https://github.com/miguelgrinberg/microdot/security/advisories/GHSA-7wc8-wvc4-m498 · Note
• https://github.com/advisories/GHSA-7wc8-wvc4-m498 · Note
• https://pypi.org/project/microdot · Note