CVE-2026-69211

MEDIUMCVSS 4.8/10EPSS 0.22%

Last modified

CVE-2026-69211 is a medium-severity vulnerability rated 4.8/10 on the CVSS scale. Http4s is a Scala interface for HTTP services. Prior to 0.23.35 and 1.0.0-M47, ResponseCookie.render writes attacker-influenced name, content, domain, path, and extension values without neutralizing semicolons or control characters. EPSS estimates a 0.22% chance of exploitation in the next 30 days.

Description

Http4s is a Scala interface for HTTP services. Prior to 0.23.35 and 1.0.0-M47, ResponseCookie.render writes attacker-influenced name, content, domain, path, and extension values without neutralizing semicolons or control characters. An application that constructs a ResponseCookie from unvalidated input can therefore emit injected cookie attributes such as Domain, Path, or SameSite, widening cookie scope or weakening protections, and control characters may enable header splitting on permissive backends. The patch strips control characters from all five fields and strips semicolons from name, content, domain, and path while retaining the extension delimiter behavior. This issue is fixed in versions 0.23.35 and 1.0.0-M47.

Metrics

EPSS Probability
0.22%

12.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
http4shttp4s< 0.23.35; >= 1.0.0-M1, < 1.0.0-M47

References

Timeline

Published
Last Modified
Status
Deferred

Frequently Asked Questions

What is CVE-2026-69211?
Http4s is a Scala interface for HTTP services. Prior to 0.23.35 and 1.0.0-M47, ResponseCookie.render writes attacker-influenced name, content, domain, path, and extension values without neutralizing semicolons or control characters. An application that constructs a ResponseCookie from unvalidated input can therefore emit injected cookie attributes such as Domain, Path, or SameSite, widening cookie scope or weakening protections, and control characters may enable header splitting on permissive backends. The patch strips control characters from all five fields and strips semicolons from name, content, domain, and path while retaining the extension delimiter behavior. This issue is fixed in versions 0.23.35 and 1.0.0-M47.
How severe is CVE-2026-69211?
CVE-2026-69211 has a CVSS score of 4.8/10 (MEDIUM severity). The EPSS model estimates a 0.22% probability of exploitation in the next 30 days.
How do I fix CVE-2026-69211?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST