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

Status: published. Published: 2026-01-07. Updated: 2026-11-08.

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.

## Remediation

- fix: The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches. (source: CNA: VulnCheck) — https://github.com/openflagr/flagr/releases/tag/1.1.19

## Affected products and versions

- OpenFlagr / Flagr (github.com/openflagr/flagr): ≥ 0; ≤ 1.1.18 (affected, semver). Source: CNA: VulnCheck

## Severity and prioritization

- CVSS 4.0: 9.3 (critical); 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; source: CNA: VulnCheck

- CISA KEV: No listing in collected sources

- EPSS: 1.52% as of 2026-11-08; percentile 74.75%

- SSVC: exploitation poc; automatable yes; technical impact total; source ADP: CISA-ADP

- Weaknesses: CWE-306, CWE-425

## Exploit evidence

- exploit: https://dreyand.rs/code%20review/golang/2026/01/03/0day-speedrun-openflagr-less-1118-authentication-bypass (CNA: VulnCheck)

## References

- https://github.com/openflagr/flagr/releases/tag/1.1.19 (CNA: VulnCheck; release-notes, patch)

- https://dreyand.rs/code%20review/golang/2026/01/03/0day-speedrun-openflagr-less-1118-authentication-bypass (CNA: VulnCheck; technical-description, exploit)

- https://www.vulncheck.com/advisories/openflagr-authentication-bypass-via-prefix-whitelist-path-normalization (CNA: VulnCheck; third-party-advisory)

## Provenance

- CNA: VulnCheck: https://www.cve.org/CVERecord?id=CVE-2026-0650; retrieved 2026-11-08; source updated 2026-11-08

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-0650; retrieved 2026-11-08; source updated Not reported

Revision: 96f6c2c55a52cfb9cb8a83e1ec1942428ffa844e1792e98c8cfc77d44f47d2a0

Canonical: https://y2.dev/cve/CVE-2026-0650

## Agent and API access

Public CVE pages, Markdown, and JSON are free to read without an account or API key.

- Public catalog: https://y2.dev/cve/index.json. Follow nextCursor with the same search, filters, sort, and limit (1–100). A null cursor marks the end.

- WebMCP: search_cve_disclosures, get_cve_disclosure, get_cve_page_markdown, get_y2_cve_access. Available in compatible browsers.

- Cyber API: https://api.y2.dev/api/v2/cyber/cves and https://api.y2.dev/api/v2/cyber/cves/{cveId}.

- Y2 Pro or Elite: create a workspace API key with the intel:cyber scope and send Authorization: Bearer <Y2_API_KEY>. Setup: https://y2.dev/docs/api/create-key.

- x402: Pay per request without an account or API key. Omit Authorization, read the HTTP 402 PAYMENT-REQUIRED challenge, validate its current requirements, and retry with PAYMENT-SIGNATURE through an authorized payment client. These browser tools never make payments. Guide: https://y2.dev/docs/api/x402.

- OpenAPI: https://y2.dev/api/openapi.yaml. Agent access metadata: https://y2.dev/cve/agent.json.

Collected public records only. Check source status for coverage and freshness.