Cookie Scoping Bypass in http4k Affecting Client Security
CVE-2026-100725

8.3HIGH

Key Information:

Vendor

Http4k

Status
Http4k
Vendor
CVE Published:
27 September 2026

What is CVE-2026-100725?

The BasicCookieStorage component in http4k exists without proper enforcement of RFC 6265 scoping rules for cookie domain, path, and Secure attributes. This issue arises when a single BasicCookieStorage instance is utilized across multiple origins or schemes, leading to the inadvertent sharing of cookies between different origins. This risk allows Secure cookies to be transmitted over non-secure HTTP connections, potentially exposing critical session information and sensitive data to unauthorized entities or network observers. Clients should ensure that cookie storage is scoped to a single origin to mitigate these risks.

Affected Version(s)

http4k 0 < 6.48.0.0

http4k 0 < 5.42.0.0

http4k 0 < 4.51.0.0

References

https://github.com/http4k/http4k/security/advisories/GHSA...
vendor-advisory
https://github.com/http4k/http4k/commit/6a9b44d743
patch
https://www.vulncheck.com/advisories/http4k-before-6.48.0...
third-party-advisory

CVSS V4

Score:
8.3
Severity:
HIGH
Confidentiality:
High
Integrity:
Low
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
Physical
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.