# CVE-2026-0650: OpenFlagr <= 1.1.18 Authentication Bypass via Prefix Whitelist Path Normalization

> Attackers can bypass authentication via path normalization flaws to access protected APIs, modify feature flags, and export sensitive data.

- **Severity:** Critical 9.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 7 Jan 2026
- **Updated:** 8 Oct 2026
- **Also known as:** GHSA-rwp9-5g7q-73q3, GO-2026-4286

## What is CVE-2026-0650?

CVE-2026-0650 is a critical authentication bypass vulnerability in OpenFlagr Flagr, published on 7 Jan 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

OpenFlagr versions prior to and including 1.1.18 contain an authentication bypass vulnerability in the HTTP middleware. Due to improper handling of path normalization in the whitelist logic, crafted requests can bypass authentication and access protected API endpoints without valid credentials. Unauthorized access may allow modification of feature flags and export of sensitive data.

Weakness: CWE-425 (Direct Request), CWE-306 (Missing Authentication for Critical Functionality)

## Which versions are affected by CVE-2026-0650?

3 open source packages ship an affected version, including github.com/openflagr/flagr.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/openflagr/flagr` | Go | All versions | 0.0.0-20251009103504-fe83dc87aa40 |
| `github.com/openflagr/flagr` | Go | All versions | 0.0.0-20251009103504-fe83dc87aa40 |
| `github.com/openflagr/flagr` | Go | All versions | 0.0.0-20251009103504-fe83dc87aa40 |

## How do I fix CVE-2026-0650?

Upgrade github.com/openflagr/flagr to 0.0.0-20251009103504-fe83dc87aa40 or later.

## Is CVE-2026-0650 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-0650 exists.

Public exploit code:

- OpenFlagr <= 1.1.18 - Authentication Bypass (nuclei): http/cves/2026/CVE-2026-0650.yaml

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-0650 and fix it if it is affected.

What it is: CVE-2026-0650 is a critical authentication bypass vulnerability in OpenFlagr Flagr, published on 7 Jan 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-0650 exists.

Affected packages and fixed versions:
- github.com/openflagr/flagr (Go): affected all versions; fixed in 0.0.0-20251009103504-fe83dc87aa40
- github.com/openflagr/flagr (Go): affected all versions; fixed in 0.0.0-20251009103504-fe83dc87aa40
- github.com/openflagr/flagr (Go): affected all versions; fixed in 0.0.0-20251009103504-fe83dc87aa40

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-2026-0650/ (Markdown: https://insights.sbomify.com/CVE-2026-0650/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-0650
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-0650
- OSV: https://osv.dev/vulnerability/CVE-2026-0650

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-0650/
Summaries are generated and may contain mistakes; the official description above is the record.