CVE-2026-69214 Http4s: CookieJar middleware accepts arbitrary Set-Cookie domain

What is CVE-2026-69214?

CVE-2026-69214 is a medium-severity vulnerability in http4s, published on 15 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

Http4s is a Scala interface for HTTP services. Prior to 0.23.35 and 1.0.0-M47, The CookieJar client middleware stores a response cookie’s Domain attribute without checking that it domain-matches the host that supplied the cookie or rejecting public suffixes. A malicious or compromised server contacted through the same CookieJar can plant a cookie for another domain, and the jar later sends that cookie to the victim domain, enabling session fixation or overwriting security-sensitive cookies. The patch validates the Set-Cookie domain against the response origin, although public-suffix rejection remains unimplemented. This issue is fixed in versions 0.23.35 and 1.0.0-M47.

Weakness: CWE-565, CWE-384

Which versions are affected by CVE-2026-69214?

10 open source packages ship an affected version, including org.http4s:http4s-client_2.13, org.http4s:http4s-client_2.12 and org.http4s:http4s-client_3.

How do I fix CVE-2026-69214?

Upgrade org.http4s:http4s-client_2.13 to a fixed version for your release line: 0.23.35 or 1.0.0-M47.

Is CVE-2026-69214 being exploited?

There is no known exploitation of CVE-2026-69214 in the wild and no public exploit code.

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-wv64-j4fq-5f9x.