# GHSA-m23h-6mwm-39m8: A vulnerability in the Kong Ingress Controller (KIC) allows for the unauthorized exfiltration of TLS certificates and private key > Low-privileged users can exfiltrate TLS secrets from other namespaces by creating Gateways in managed mode, bypassing ReferenceGrant restrictions. - **Severity:** Not scored - **Exploited in the wild:** Not known - **Login needed:** Any signed-in user - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 19 May 2026 - **Also known as:** GO-2026-5485 ## What is GHSA-m23h-6mwm-39m8? GHSA-m23h-6mwm-39m8 is a missing authorization vulnerability in github.com/kong/kubernetes-ingress-controller, published on 19 May 2026. Any signed-in user can exploit it over the network, with no action from the victim. ### Official description ## Summary A vulnerability in the Kong Ingress Controller (KIC) allows for the unauthorized exfiltration of TLS certificates and private keys across Kubernetes namespace boundaries. In "managed" mode (where the `GatewayClass` lacks an unmanaged annotation), the Gateway TLS translator skips critical status checks. This bypass allows the translator to fetch Secrets from any namespace KIC watches, even when a `ReferenceGrant` explicitly denies access or is missing. An actor with RBAC permissions to create or modify Gateways in a low-privileged namespace can reference a Secret in a high-privileged namespace, causing KIC to "leak" that Secret's sensitive private key material into the Kong dataplane configuration. ## Am I affected? You are affected if all of these hold: 1. You are using Kong Ingress Controller with the **Gateway API**. 2. Your `GatewayClass` is operating in **managed mode** (default behavior, no unmanaged annotation). 3. KIC is configured to **watch multiple namespaces** (multi-tenant environment). 4. Users have RBAC permissions to `create` or `update` `gateways.gateway.networking.k8s.io` in their own namespaces. You are not affected if any of this: - You only use KIC for `Ingress` resources (not Gateway API). - Your `GatewayClass` uses the `konghq.com/gateway-unmanaged` annotation. - KIC is restricted via RBAC or configuration to only watch a single namespace. - You have strictly limited Gateway creation/modification permissions to trusted cluster administrators only. ## Mitigation 1. **Add unmanaged gateway annotation**: add the `konghq.com/gateway-unmanaged` annotation to your `GatewayClass` ### Additional best practicies 1. **Restrict Gateway RBAC**: Limit the ability to create or modify Gateway resources to high-trust administrative users until a patch is applied. 2. **Namespace Isolation**: If possible, limit the namespaces KIC is permitted to watch using the `WATCH_NAMESPACE` environment variable or specific RBAC RoleBindings. ## Fix The fix mandates `ReferenceGrant` validation for all cross-namespace certificate references. By requiring a `Programmed: True` listener status, the translator now strictly authorizes external Secret access while maintaining default access for same-namespace certificates, effectively closing the exfiltration vector. Fixed in [#7920](https://github.com/Kong/kubernetes-ingress-controller/pull/7920), with backports to supported release branches in [#7921](https://github.com/Kong/kubernetes-ingress-controller/pull/7921) and [#7922](https://github.com/Kong/kubernetes-ingress-controller/pull/7922). Upgrade to one of the following patched versions (or later): - **3.4.14** - **3.5.7** ## CVSS `CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N/E:P` = **5.6 Medium** ## Which versions are affected by GHSA-m23h-6mwm-39m8? 11 open source packages ship an affected version, including github.com/kong/kubernetes-ingress-controller/v3, github.com/kong/kubernetes-ingress-controller and github.com/kong/kubernetes-ingress-controller/v2. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `github.com/kong/kubernetes-ingress-controller/v3` | Go | All versions | 3.4.14, 3.5.7 | | `github.com/kong/kubernetes-ingress-controller/v3` | Go | All versions | 3.4.14 | | `github.com/kong/kubernetes-ingress-controller/v3` | Go | All versions | 3.4.14 | | `github.com/kong/kubernetes-ingress-controller/v3` | Go | From 3.5.0 | 3.5.7 | | `github.com/kong/kubernetes-ingress-controller/v3` | Go | From 3.5.0 | 3.5.7 | | `github.com/kong/kubernetes-ingress-controller` | Go | All versions | None | | `github.com/kong/kubernetes-ingress-controller` | Go | All versions to 1.3.4 | None | | `github.com/kong/kubernetes-ingress-controller` | Go | All versions to 1.3.4 | None | | `github.com/kong/kubernetes-ingress-controller/v2` | Go | All versions | None | | `github.com/kong/kubernetes-ingress-controller/v2` | Go | All versions to 2.12.8 | None | | `github.com/kong/kubernetes-ingress-controller/v2` | Go | All versions to 2.12.8 | None | ## How do I fix GHSA-m23h-6mwm-39m8? Upgrade github.com/kong/kubernetes-ingress-controller/v3 to a fixed version for your release line: 3.4.14 or 3.5.7. ## Is GHSA-m23h-6mwm-39m8 being exploited? There is no known exploitation of GHSA-m23h-6mwm-39m8 in the wild and no public exploit code. ## Fix prompt for AI coding agents ```text Check this codebase for GHSA-m23h-6mwm-39m8 and fix it if it is affected. What it is: GHSA-m23h-6mwm-39m8 is a missing authorization vulnerability in github.com/kong/kubernetes-ingress-controller, published on 19 May 2026. Any signed-in user can exploit it over the network, with no action from the victim. Exploitation: There is no known exploitation of GHSA-m23h-6mwm-39m8 in the wild and no public exploit code. Affected packages and fixed versions: - github.com/kong/kubernetes-ingress-controller/v3 (Go): affected all versions; fixed in 3.4.14, 3.5.7 - github.com/kong/kubernetes-ingress-controller/v3 (Go): affected all versions; fixed in 3.4.14 - github.com/kong/kubernetes-ingress-controller/v3 (Go): affected all versions; fixed in 3.4.14 - github.com/kong/kubernetes-ingress-controller/v3 (Go): affected from 3.5.0; fixed in 3.5.7 - github.com/kong/kubernetes-ingress-controller/v3 (Go): affected from 3.5.0; fixed in 3.5.7 - github.com/kong/kubernetes-ingress-controller (Go): affected all versions; no fix listed - github.com/kong/kubernetes-ingress-controller (Go): affected all versions up to 1.3.4; no fix listed - github.com/kong/kubernetes-ingress-controller (Go): affected all versions up to 1.3.4; no fix listed - github.com/kong/kubernetes-ingress-controller/v2 (Go): affected all versions; no fix listed - github.com/kong/kubernetes-ingress-controller/v2 (Go): affected all versions up to 2.12.8; no fix listed - github.com/kong/kubernetes-ingress-controller/v2 (Go): affected all versions up to 2.12.8; no fix listed Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/GHSA-m23h-6mwm-39m8/ (Markdown: https://insights.sbomify.com/GHSA-m23h-6mwm-39m8/index.md) ``` ## Sources - OSV: https://osv.dev/vulnerability/GHSA-m23h-6mwm-39m8 --- From sbomify Insights: https://insights.sbomify.com/GHSA-m23h-6mwm-39m8/ Summaries are generated and may contain mistakes; the official description above is the record.