# Symfony has a UrlGenerator Route-Requirement Bypass via Unanchored Regex Alternation → Off-Site //host URL Injection Advisory record · `GHSA-72xp-p242-47p9` - **Identifiers:** `GHSA-72xp-p242-47p9` · `CVE-2026-45065` · `PKSA-3f27-q682-kfn9` · `PKSA-yc7t-91v9-99xs` - **State:** Confirmed - **Severity:** CVSS 2.3 Low - **Critical:** No - **Weakness (CWE):** [CWE-185](https://cwe.mitre.org/data/definitions/185.html) · [CWE-601](https://cwe.mitre.org/data/definitions/601.html) - **Tags:** [Open redirect](https://agentprime.io/advisories/tag/open-redirect.md) · [CWE-185](https://agentprime.io/advisories/tag/cwe-185.md) - **Published:** 27 May 2026 - **Updated:** 10 Sept 2026 - **Reviewed by a person:** No Published by the GitHub Advisory Database at 27 May 2026, 16:55 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. ## Affected packages - `symfony/routing` (Packagist): affected `<5.4.52 || >=6.0.0, <6.4.40 || >=7.0.0, <7.4.12 || >=8.0.0, <8.0.12`; fixed in `5.4.52`, `6.4.40`, `7.4.12`, `8.0.12` - `symfony/symfony` (Packagist): affected `<5.4.52 || >=6.0.0, <6.4.40 || >=7.0.0, <7.4.12 || >=8.0.0, <8.0.12`; fixed in `5.4.52`, `6.4.40`, `7.4.12`, `8.0.12` ## Machine-written summary Summary written by Claude Haiku from the source advisory. Not reviewed by a person. > Symfony's routing component (symfony/routing and symfony/symfony) before 5.4.52, 6.4.40, 7.4.12 and 8.0.12 is affected. The UrlGenerator anchors only the first and last alternatives of a route requirement regex, so a value containing a middle alternative can pass validation and produce a protocol-relative "//host" URL that leads off-site. The source does not state what an attacker needs beyond supplying such a value, nor the full impact. Upgrade to 5.4.52, 6.4.40, 7.4.12, 8.0.12 or later. Written 31 Oct 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 - 2.3 Low, CVSS 4.0: `CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N`, from CNA (GitHub_M) - **CISA KEV:** Not listed. - **EPSS:** 0.0035, the 28th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days. ## Timeline - 31 Oct 2026, 14:02 UTC: First seen by agentprime - 31 Oct 2026, 14:02 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-72xp-p242-47p9) ## Sources - [GitHub Advisory Database: GHSA-72xp-p242-47p9](https://github.com/advisories/GHSA-72xp-p242-47p9) - [OSV: GHSA-72xp-p242-47p9](https://osv.dev/vulnerability/GHSA-72xp-p242-47p9) - - - - - - 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: .