Summary
Http4s: CookieJar middleware matches by substring, leaking cookies cross-origin
The CookieJar client middleware decides whether to attach a cookie to an outgoing request using an unanchored substring test on the host and path, instead of the domain match specified by RFC6265 5.1.3. A cookie stored for example.com is therefore sent to any host whose name merely contains example.com (e.g. evilexample.com), leaking potentially sensitive cookies to an attacker-chosen host.
Preconditions
- Application uses the
CookieJarclient middleware. - Application can be induced to make an outbound request to a host controlled by the attacker, where the hostname contains the targeted domain as a substring.
Workarounds
- Do not use the
CookieJarwith clients that fetch attacker-influenced URLs - Apply a separate
CookieJarper trusted origin.
Impact
Disclosure of session and authentication cookies to an attacker-controlled host, enabling session hijack of the application's outbound calls.
CVE-2026-69215 has a CVSS score of 6.8 (Medium). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (0.23.35, 1.0.0-M47); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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org.http4s:http4s-client_2.12 to 0.23.35 or later; org.http4s:http4s-client_2.13 to 0.23.35 or later; org.http4s:http4s-client_3 to 0.23.35 or later; org.http4s:http4s-client_2.13 to 1.0.0-M47 or later; org.http4s:http4s-client_3 to 1.0.0-M47 or later
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2026-69215? CVE-2026-69215 is a medium-severity security vulnerability in org.http4s:http4s-client_2.12 (maven), affecting versions <= 0.23.34. It is fixed in 0.23.35, 1.0.0-M47.
- How severe is CVE-2026-69215? CVE-2026-69215 has a CVSS score of 6.8 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which packages are affected by CVE-2026-69215?
org.http4s:http4s-client_2.12(maven) (versions <= 0.23.34)org.http4s:http4s-client_2.13(maven) (versions <= 0.23.34)org.http4s:http4s-client_3(maven) (versions <= 0.23.34)
- Is there a fix for CVE-2026-69215? Yes. CVE-2026-69215 is fixed in 0.23.35, 1.0.0-M47. Upgrade to this version or later.
- Is CVE-2026-69215 exploitable, and should I be worried? Whether CVE-2026-69215 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-69215 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-69215?
- Upgrade
org.http4s:http4s-client_2.12to 0.23.35 or later - Upgrade
org.http4s:http4s-client_2.13to 0.23.35 or later - Upgrade
org.http4s:http4s-client_3to 0.23.35 or later - Upgrade
org.http4s:http4s-client_2.13to 1.0.0-M47 or later - Upgrade
org.http4s:http4s-client_3to 1.0.0-M47 or later
- Upgrade