# Traefik: Deny Rule Bypass via Unauthenticated Malicious gRPC Requests in gRPC-Go Dependency (CVE-2026-33186) Advisory record · `GHSA-46wh-3698-f2cx` - **Identifiers:** `GHSA-46wh-3698-f2cx` · `GO-2026-4897` - **State:** Confirmed - **Severity:** CVSS 4.0, no score published - **Critical:** No - **Weakness (CWE):** [CWE-285](https://cwe.mitre.org/data/definitions/285.html) · [CWE-1395](https://cwe.mitre.org/data/definitions/1395.html) - **Tags:** [Broken access control](https://agentprime.io/advisories/tag/access-control.md) · [CWE-1395](https://agentprime.io/advisories/tag/cwe-1395.md) - **Published:** 29 Mar 2026 - **Updated:** 10 Sept 2026 - **Reviewed by a person:** No Published by the GitHub Advisory Database at 29 Mar 2026, 15:37 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. ## Affected packages - `github.com/traefik/traefik/v2` (Go): affected `<2.11.42`; fixed in `2.11.42` - `github.com/traefik/traefik/v3` (Go): affected `>=3.0.0-beta3, <3.6.12 || >=3.7.0-ea.1, <3.7.0-ea.3`; fixed in `3.6.12`, `3.7.0-ea.3` ## Machine-written summary Summary written by Claude Haiku from the source advisory. Not reviewed by a person. > Traefik v2 before 2.11.42 and Traefik v3 from 3.0.0-beta3 before 3.6.12, plus 3.7.0-ea.1 before 3.7.0-ea.3, are affected through a vulnerable gRPC-Go dependency. A remote, unauthenticated attacker can send gRPC requests with a malformed HTTP/2 :path lacking the leading slash, which can bypass path-based deny rules when a fallback allow rule exists. Upgrade to Traefik 2.11.42, 3.6.12, or 3.7.0-ea.3, depending on the release line in use. Written 1 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 - Score not published, CVSS 4.0: `CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N`, from GitHub Advisory Database - **CISA KEV:** Not listed. - **EPSS:** No score. ## Timeline - 31 Oct 2026, 14:14 UTC: First seen by agentprime - 31 Oct 2026, 14:14 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-46wh-3698-f2cx) ## Sources - [GitHub Advisory Database: GHSA-46wh-3698-f2cx](https://github.com/advisories/GHSA-46wh-3698-f2cx) - [OSV: GHSA-46wh-3698-f2cx](https://osv.dev/vulnerability/GHSA-46wh-3698-f2cx) - - - - - - - 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: .