# CVE-2026-33376: Auth Proxy IPv6 whitelist bypass

> Attackers can bypass IPv6 allow-list restrictions in Grafana's Auth Proxy feature due to incorrect default subnet masking, requiring manual configuration updates.

- **Severity:** High 7.4 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 13 May 2026
- **Updated:** 27 Aug 2026
- **Also known as:** BIT-grafana-2026-33376, GHSA-3r2p-7499-27q3, MINI-28m3-5v2q-6qrw, MINI-3r52-84rf-gfm8, MINI-4jj3-5q44-59m8, MINI-6w92-m35j-w97p, MINI-8g72-c866-6qhr, MINI-8x8q-xprw-mr72, MINI-966j-w9w6-4m2x, MINI-gcjx-875q-gpmf, MINI-h27q-q64w-mmwg, MINI-jmcx-hhxc-h8rx, MINI-jv8x-xqf2-f984, MINI-jxr2-66jf-xr33, MINI-pc3q-gfxc-pwcv, MINI-v47x-9gwx-6p27, MINI-vgqj-56p7-8wxr, MINI-xvpc-mm96-cpgf, UBUNTU-CVE-2026-33376

## What is CVE-2026-33376?

CVE-2026-33376 is a high-severity authentication bypass vulnerability in Grafana Grafana, published on 13 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

When using an IPv6 allow-list for the Auth Proxy feature, it defaults to /32 addresses. Addresses specifying a mask explicitly are not affected; to mitigate easily, add the desired mask (usually /128) to the addresses. Only auth proxy is affected; Okta, SAML, LDAP, etc are unaffected here.

Weakness: CWE-1188 (Initialization of a Resource with an Insecure Default)

## Which versions are affected by CVE-2026-33376?

1 open source package ship an affected version, including grafana. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `grafana` | Bitnami | From 9.4.0 | 11.6.14, 12.2.8, 12.3.6, 12.4.3, 13.0.1 |

Products: Grafana Grafana.

## How do I fix CVE-2026-33376?

Upgrade grafana to a fixed version for your release line: 11.6.14, 12.2.8, 12.3.6 or 12.4.3.

## Is CVE-2026-33376 being exploited?

There is no known exploitation of CVE-2026-33376 in the wild and no public exploit code.

## Other vulnerabilities in Grafana Grafana

- [CVE-2021-43798](https://insights.sbomify.com/CVE-2021-43798/): Grafana Path Traversal (high 7.5, exploited in the wild)
- [CVE-2025-41115](https://insights.sbomify.com/CVE-2025-41115/): Incorrect privilege assignment (critical 10.0)
- [CVE-2022-39328](https://insights.sbomify.com/CVE-2022-39328/): Grafana vulnerable to race condition allowing privilege escalation (critical 9.8)
- [CVE-2022-28660](https://insights.sbomify.com/CVE-2022-28660/): Auth bypass in n/a (critical 9.8)
- [CVE-2022-26148](https://insights.sbomify.com/CVE-2022-26148/): Information disclosure in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-33376 and fix it if it is affected.

What it is: CVE-2026-33376 is a high-severity authentication bypass vulnerability in Grafana Grafana, published on 13 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-33376 in the wild and no public exploit code.

Affected packages and fixed versions:
- grafana (Bitnami): affected from 9.4.0; fixed in 11.6.14, 12.2.8, 12.3.6, 12.4.3, 13.0.1

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/CVE-2026-33376/ (Markdown: https://insights.sbomify.com/CVE-2026-33376/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-33376
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-33376
- OSV: https://osv.dev/vulnerability/CVE-2026-33376

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-33376/
Summaries are generated and may contain mistakes; the official description above is the record.