Vulnerability GHSA-pr33-38xx-6r26

Medium Risk
MEDIUM RISK
CVSS Score: 6.0
Score Range: 4.0–6.9
Medium severity vulnerabilities (CVSS 4.0–6.9). Important issues that meaningfully reduce security confidence.
3 months ago
June 19, 2026 at 09:16 PM UTC
http4k: BasicCookieStorage` (renamed `InsecureCookieStorage`) did not enforce RFC 6265 cookie scoping; new `DefaultCookieStorage` is now the default
v6.3.0.0 - 0.22.0
v6.3.0.0 - 0.22.0

Summary

http4k: BasicCookieStorage` (renamed `InsecureCookieStorage`) did not enforce RFC 6265 cookie scoping; new `DefaultCookieStorage` is now the default

Details

Impact

The previous BasicCookieStorage did not enforce RFC 6265 scoping rules around cookie domain, path, and Secure attribute. A client using a single storage instance to talk to multiple origins could have cookies leak across domains, or have Secure cookies sent over plain HTTP — the deprecation message states it bluntly: "BasicCookieStorage has no domain/path/scheme scoping and leaks cookies across origins. Use DefaultCookieStorage instead."

Who is affected: any client using BasicCookieStorage directly with cookies for more than one origin or scheme. Single-origin uses are unaffected.

Patches

Line Fixed in Edition
v6.x (Community) 6.48.0.0 Community
v5.x (LTS) 5.42.0.0 Enterprise — contact [email protected]
v4.x (LTS) 4.51.0.0 Enterprise — contact [email protected]

The fix introduces DefaultCookieStorage (RFC 6265 compliant) as the drop-in default; BasicCookieStorage is renamed InsecureCookieStorage and remains available for callers with a deliberate need for the old behaviour.

Workarounds

For deployments that cannot upgrade immediately:

  • Use a dedicated BasicCookieStorage instance per origin / scheme, or
  • Switch to a separate RFC 6265-compliant cookie store implementation.

References

Impacted packages

Timeline

Published
3 months ago
June 19, 2026 at 09:16 PM UTC
Fixed (6.48.0.0)
Unknown
Unknown
Fixed (5.42.0.0)
Unknown
Unknown
Last Modified
23 hours ago
September 27, 2026 at 11:56 AM UTC