# Http4s: CookieJar middleware accepts arbitrary Set-Cookie domain Advisory record · `GHSA-wv64-j4fq-5f9x` - **Identifiers:** `GHSA-wv64-j4fq-5f9x` · `CVE-2026-69214` - **State:** Confirmed - **Severity:** CVSS 6.8 Medium - **Critical:** No - **Weakness (CWE):** [CWE-384](https://cwe.mitre.org/data/definitions/384.html) · [CWE-565](https://cwe.mitre.org/data/definitions/565.html) - **Tags:** [Authentication bypass](https://agentprime.io/advisories/tag/auth-bypass.md) · [CWE-565](https://agentprime.io/advisories/tag/cwe-565.md) - **Published:** 15 Sept 2026 - **Updated:** 15 Sept 2026 - **Reviewed by a person:** No Published by the GitHub Advisory Database at 15 Sept 2026, 20:00 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. ## Affected packages - `org.http4s:http4s-client_2.12` (Maven): affected `<0.23.35`; fixed in `0.23.35` - `org.http4s:http4s-client_2.13` (Maven): affected `<0.23.35 || >=1.0.0-M1, <1.0.0-M47`; fixed in `0.23.35`, `1.0.0-M47` - `org.http4s:http4s-client_3` (Maven): affected `>=1.0.0-M1, <1.0.0-M47 || <0.23.35`; fixed in `1.0.0-M47`, `0.23.35` ## Machine-written summary Summary written by Claude Haiku from the source advisory. Not reviewed by a person. > The http4s-client package is affected in several version ranges: below 0.23.35 for the 2.12 and 2.13 builds, 1.0.0-M1 up to 1.0.0-M47 for the 2.13 and 3 builds, and below 0.23.35 for the 3 build. The CookieJar client middleware accepts a Domain attribute from a server's Set-Cookie header without checking that it matches the sending host. A malicious or compromised server can plant cookies for other domains in the same jar, enabling session fixation or overwriting of security-relevant cookies. Upgrade to 0.23.35 or 1.0.0-M47. Avoid sharing one CookieJar between trusted and untrusted servers. Written 2 Nov 2026. ## Not analysed yet We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check. ## Severity and exploitation - 6.8 Medium, CVSS 3.1: `CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N`, from CNA (GitHub_M) - **CISA KEV:** Not listed. - **EPSS:** 0.0040, the 33rd percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days. ## Timeline - 31 Oct 2026, 14:16 UTC: First seen by agentprime - 31 Oct 2026, 14:16 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-wv64-j4fq-5f9x) ## Sources - [GitHub Advisory Database: GHSA-wv64-j4fq-5f9x](https://github.com/advisories/GHSA-wv64-j4fq-5f9x) - [OSV: GHSA-wv64-j4fq-5f9x](https://osv.dev/vulnerability/GHSA-wv64-j4fq-5f9x) - - - - - Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code. ## Check whether this affects you A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet. - With the agentprime MCP server (), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: - In a browser: reads your lockfile in the browser, never uploading it. - Whether it touches your code, with file and line: the Claude Code plugin, - As JSON: , or `POST https://api.agentprime.io/v1/match` with your packages () --- The web page: . Everything for agents: .