# Default CORS config allows any origin with credentials Advisory record · `GHSA-52cf-226f-rhr6` - **Identifiers:** `GHSA-52cf-226f-rhr6` · `CVE-2021-39185` - **State:** Confirmed - **Severity:** CVSS 9.1 Critical - **Critical:** Yes: CVSS 9+ - **Weakness (CWE):** [CWE-346](https://cwe.mitre.org/data/definitions/346.html) - **Tags:** [CWE-346](https://agentprime.io/advisories/tag/cwe-346.md) - **Published:** 2 Sept 2021 - **Updated:** 8 Jul 2026 - **Reviewed by a person:** No Published by the GitHub Advisory Database at 2 Sept 2021, 16:52 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. ## Critical Critical, because: - CVSS score 9.1: 9.0 or more. How we decide what’s critical: ## Affected packages - `org.http4s:http4s-server_2.13.0-M5` (Maven): affected `all versions`; no fixed version yet - `org.http4s:http4s-server_3` (Maven): affected `>=0.22.0, <0.22.3 || >=0.23.0, <0.23.2`; fixed in `0.22.3`, `0.23.2` - `org.http4s:http4s-server_2.10` (Maven): affected `all versions`; no fixed version yet - `org.http4s:http4s-server_2.11` (Maven): affected `all versions`; no fixed version yet - `org.http4s:http4s-server_2.12` (Maven): affected `<0.21.27 || >=0.22.0, <0.22.3 || >=0.23.0, <0.23.2`; fixed in `0.21.27`, `0.22.3`, `0.23.2` - `org.http4s:http4s-server_2.13` (Maven): affected `<0.21.27 || >=0.22.0, <0.22.3 || >=0.23.0, <0.23.2`; fixed in `0.21.27`, `0.22.3`, `0.23.2` ## Machine-written summary Summary written by Claude Haiku from the source advisory. Not reviewed by a person. > The http4s-server package (Maven, Scala 2.12, 2.13 and 3 builds) is affected in versions before 0.21.27, from 0.22.0 before 0.22.3, and from 0.23.0 before 0.23.2, because its default CORS configuration reflects any origin while allowing credentials. An attacker who gets a user to visit a malicious page can read sensitive responses from the vulnerable site using that user's credentials. Upgrade to 0.21.27, 0.22.3, 0.23.2, or a later release; the deprecated CORS and CORSConfig should be replaced with the new CORSPolicy. 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 - 9.1 Critical, CVSS 3.1: `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N`, from CNA (GitHub_M) - **CISA KEV:** Not listed. - **EPSS:** 0.0059, the 48th percentile, on 11 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days. ## Timeline - 31 Oct 2026, 14:20 UTC: First seen by agentprime - 31 Oct 2026, 14:20 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-52cf-226f-rhr6) ## Sources - [GitHub Advisory Database: GHSA-52cf-226f-rhr6](https://github.com/advisories/GHSA-52cf-226f-rhr6) - [OSV: GHSA-52cf-226f-rhr6](https://osv.dev/vulnerability/GHSA-52cf-226f-rhr6) - - - - 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: .