http4k before 6.48.0.0 Cookie Scoping Bypass via BasicCookieStorage (CVE-2026-100725) | HOL Guard CVE

High · CVSS 8.3CVE-2026-100725

http4k before 6.48.0.0 Cookie Scoping Bypass via BasicCookieStorage

Answer in brief

CVE-2026-100725 records a High severity (CVSS 8.3) vulnerability in http4k before 6.48.0.0 Cookie Scoping Bypass via BasicCookieStorage. The current sources do not mark it as known exploited. The current feed maps http4k/http4k (generic), http4k/http4k (generic), http4k/http4k (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 27, 2026Updated Sep 27, 2026Source checked Sep 27, 2026First seen by HOL Sep 27, 2026Material review Sep 27, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 8.3
Exploitation: Not marked as known exploited
Affected software: 3 mapped packages or products
Fix availability: Available

Why this deserves its current priority

CVSS is 8.3. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps http4k/http4k (generic), http4k/http4k (generic), http4k/http4k (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
http4k/http4kgeneric	>=0 <6.48.0.0	6.48.0.0
http4k/http4kgeneric	>=0 <5.42.0.0	5.42.0.0
http4k/http4kgeneric	>=0 <4.51.0.0	4.51.0.0

Recommended response

Check inventory. Check lockfiles and deployed manifests for http4k/http4k, http4k/http4k, http4k/http4k.
Review the reported fix. Update http4k/http4k to 6.48.0.0; http4k/http4k to 5.42.0.0; http4k/http4k to 4.51.0.0 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 27, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 27, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 27, 2026

Sources and claim methodology

Upstream source description

http4k (Maven artifact org.http4k:http4k-core) before 6.48.0.0, 5.42.0.0, and 4.51.0.0 ships a BasicCookieStorage (client-side cookie store used by ClientFilters.Cookies) that does not enforce RFC 6265 scoping rules for the cookie domain, path, and Secure attributes. When a single BasicCookieStorage instance is used to talk to more than one origin or scheme, cookies stored for one origin can be sent to other origins, and cookies marked Secure can be sent over plain HTTP, potentially disclosing session cookies or other sensitive values to unauthorized hosts or network observers. Clients that use a storage instance for a single origin are not affected.

Quoted source text, attributed separately from HOL analysis.