# Heimdall: Path received via Envoy gRPC corrupted when containing query string

Advisory record · `GHSA-r8x2-fhmf-6mxp`

- **Identifiers:** `GHSA-r8x2-fhmf-6mxp` · `CVE-2026-32811` · `GO-2026-4742`
- **State:** Confirmed
- **Severity:** CVSS 8.2 High
- **Critical:** No
- **Weakness (CWE):** [CWE-116](https://cwe.mitre.org/data/definitions/116.html) · [CWE-863](https://cwe.mitre.org/data/definitions/863.html)
- **Tags:** [Broken access control](https://agentprime.io/advisories/tag/access-control.md) · [CWE-116](https://agentprime.io/advisories/tag/cwe-116.md)
- **Published:** 18 Mar 2026
- **Updated:** 27 Apr 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 18 Mar 2026, 13:00 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `github.com/dadrus/heimdall` (Go): affected `>=0.7.0-alpha, <0.17.11`; fixed in `0.17.11`

## Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

> Heimdall versions from 0.7.0-alpha before 0.17.11 are affected when used with the Envoy gRPC decision API. Path rules without wildcards can be bypassed by adding a query string to the request, because the query is mangled into the path and no longer matches the rule. This only leads to unintended access when heimdall uses an allow-all default rule, which heimdall 0.16.0 and later refuse to start with unless enforcement is explicitly disabled. Upgrade to heimdall 0.17.11.

Written 7 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

- 8.2 High, CVSS 3.1: `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N`, from CNA (GitHub_M)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0032, the 25th percentile, on 8 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 15:08 UTC: First seen by agentprime
- 31 Oct 2026, 15:08 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-r8x2-fhmf-6mxp)

## Sources

- [GitHub Advisory Database: GHSA-r8x2-fhmf-6mxp](https://github.com/advisories/GHSA-r8x2-fhmf-6mxp)
- [OSV: GHSA-r8x2-fhmf-6mxp](https://osv.dev/vulnerability/GHSA-r8x2-fhmf-6mxp)
- <https://github.com/dadrus/heimdall/security/advisories/GHSA-r8x2-fhmf-6mxp>
- <https://nvd.nist.gov/vuln/detail/CVE-2026-32811>
- <https://github.com/dadrus/heimdall/pull/3106>
- <https://github.com/dadrus/heimdall/commit/50321b3007db1ccafdc6b1cfd6bdc3689c19a502>
- <https://github.com/dadrus/heimdall>
- <https://github.com/envoyproxy/envoy/blob/105b4acd422d67fcff908ec38d91c7676d079939/api/envoy/service/auth/v3/attribute_context.proto#L146-L147>

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 (<https://api.agentprime.io/mcp>), 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: <https://agentprime.io/mcp.md>
- In a browser: <https://agentprime.io/check/> reads your lockfile in the browser, never uploading it.
- Whether it touches your code, with file and line: the Claude Code plugin, <https://agentprime.io/plugin.md>
- As JSON: <https://api.agentprime.io/v1/advisories/GHSA-r8x2-fhmf-6mxp>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

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The web page: <https://agentprime.io/advisories/GHSA-r8x2-fhmf-6mxp/>. Everything for agents: <https://agentprime.io/llms.txt>.