{"id":"CVE-2026-69215","aliases":["GHSA-grh8-3p95-f9rr"],"url":"https://o3.security/vulnerability/CVE-2026-69215","summary":"Http4s: CookieJar middleware matches by substring, leaking cookies cross-origin","details":"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.\n\n## Impact\n\nDisclosure of session and authentication cookies to an attacker-controlled host, enabling session hijack of the application's outbound calls.\n\n## Preconditions\n\n- Application uses the `CookieJar` client middleware.\n- 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.\n\n## Workarounds\n\n- Do not use the `CookieJar` with clients that fetch attacker-influenced URLs\n- Apply a separate `CookieJar` per trusted origin.","published":"2026-09-15T19:17:12.429Z","modified":"2026-10-28T02:31:09.999765139Z","cvss":{"score":6.8,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N"},"epss":{"score":0.00426,"percentile":0.36209,"asOf":"2026-09-16"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Maven","name":"org.http4s:http4s-client_2.12","fixedVersion":"0.23.35"},{"ecosystem":"Maven","name":"org.http4s:http4s-client_2.13","fixedVersion":"0.23.35"},{"ecosystem":"Maven","name":"org.http4s:http4s-client_3","fixedVersion":"0.23.35"},{"ecosystem":"Maven","name":"org.http4s:http4s-client_2.13","fixedVersion":"1.0.0-M47"},{"ecosystem":"Maven","name":"org.http4s:http4s-client_3","fixedVersion":"1.0.0-M47"}],"fix":{"url":"https://github.com/http4s/http4s/commit/c0a37f38d5ee2a568ba57bd9da62f8d79b8b1fcc","label":"http4s/http4s@c0a37f3"},"references":[{"type":"WEB","url":"https://github.com/http4s/http4s/releases/tag/v0.23.35"},{"type":"WEB","url":"https://github.com/http4s/http4s/releases/tag/v1.0.0-M47"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/69xxx/CVE-2026-69215.json"},{"type":"ADVISORY","url":"https://github.com/http4s/http4s/security/advisories/GHSA-grh8-3p95-f9rr"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-69215"},{"type":"FIX","url":"https://github.com/http4s/http4s/commit/c0a37f38d5ee2a568ba57bd9da62f8d79b8b1fcc"},{"type":"PACKAGE","url":"https://github.com/http4s/http4s"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-10-28T02:31:09.999765139Z"}}