# Traefik Ingress in AKS does not URL-decode route parameters consistently (special characters break routing)

**URL:** <https://community.traefik.io/t/traefik-ingress-in-aks-does-not-url-decode-route-parameters-consistently-special-characters-break-routing/29749>\
**Category:** Traefik v2\
**Tags:** kubernetes-ingress\
**Created:** [March 17, 2026, 9:34am UTC](https://community.traefik.io/t/traefik-ingress-in-aks-does-not-url-decode-route-parameters-consistently-special-characters-break-routing/29749 "2026-03-17T09:34:01Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![anil.bitla](https://avatars.discourse-cdn.com/v4/letter/a/96bed5/32.png) [@anil.bitla](https://community.traefik.io/u/anil.bitla)\
**Post date:** [March 17, 2026, 9:34am UTC](https://community.traefik.io/t/traefik-ingress-in-aks-does-not-url-decode-route-parameters-consistently-special-characters-break-routing/29749/1 "2026-03-17T09:34:01Z")

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**Problem Details:**  
When route parameters contain special or encoded characters, routing fails. Examples include:

- Special characters

- Encrypted strings

- Base64 values (`+`, `/`, `=`)

- Dots (`.`)

- Encoded or unencoded slashes (`/`)

Traefik appears to treat some of these characters (especially `/`) as path separators instead of part of the parameter value.

**Observed Behavior:**

- Requests that work locally (via Kestrel) fail when routed through Traefik

- Traefik fails route matching

- Backend application returns **400 Bad Request**

- Headers (including auth tokens) are valid and unchanged

**Expected Behavior:**

- Route parameters should be passed to the backend exactly as encoded

- URL decoding behavior should be consistent with standard HTTP handling (or configurable)

- Encoded characters (e.g., `%2F`) should not break route matching

1. Is there a configuration in Traefik to control URL decoding behavior for route parameters?

2. Can Traefik be configured to preserve encoded slashes (`%2F`) instead of interpreting them as path separators?

3. Are there recommended middlewares (e.g., ReplacePathRegex, StripPrefix, etc.) to handle this scenario?

4. Is this expected behavior or a known limitation?

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<div class="post-metadata">

**Author:** ![bluepuma77](https://avatars.discourse-cdn.com/v4/letter/b/a9adbd/32.png) [@bluepuma77](https://community.traefik.io/u/bluepuma77)\
**Post date:** [March 17, 2026, 9:41am UTC](https://community.traefik.io/t/traefik-ingress-in-aks-does-not-url-decode-route-parameters-consistently-special-characters-break-routing/29749/2 "2026-03-17T09:41:33Z")

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Have you tried `http.encodedCharacters.allowEncodedSlash`, are you on Traefik latest ([old bug](https://github.com/traefik/traefik/issues/12437))?