CVE-2026-42874

3.7 LOW 0.2% exploit odds Fix listed XSS Server

What it is

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.

At a glance

Exploitability: Can be exploited over the network without logging in. Limited direct impact.
Exploit odds: 0.2% chance of exploitation in the next 30 days (EPSS).
Fix: A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

2026-05-11 20:25 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-10-26 18:10 UTC Last updatedMost recent change to the record

Why it ranks here

Exploited in the wild: no, CISA does not list it.
Exploit odds: 0.2% in the next 30 days (EPSS).
Severity: 3.7 LOW (CVSS).
Fix: a patch or advisory is linked.

Details

Published: 2026-05-11 20:25 UTC
Last modified: 2026-10-26 18:10 UTC
Exploit probability: 0.2% · EPSS, next 30 days
Weakness: CWE-113
Record status: Deferred

Attack profile CVSS 3.1 · 3.7

Attack vector: Network
Complexity: High
Privileges needed: None
User interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: Low
Availability: None

Raw vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N

Is it in your code?

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Read https://cve-list.com/agent/cve/CVE-2026-42874.md and follow it. Check whether this project is affected by CVE-2026-42874. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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Fix and advisories

References

NVD record · CVE.org record