CVE-2026-0650 — flagr
Fix: openflagr/flagr@fe83dc8CVE-2026-0650 is a Missing Authentication vulnerability in github.com/openflagr/flagr. A fix is available for github.com/openflagr/flagr — see the affected versions and patch details below.
OpenFlagr <= 1.1.18 Authentication Bypass via Prefix Whitelist Path Normalization
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-0650.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Real-World Exposure
github.com/openflagr/flagrReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/openflagr/flagr | all versions | 0.0.0-20251009103504-fe83dc87aa40go get github.com/openflagr/flagr@v0.0.0-20251009103504-fe83dc87aa40 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/openflagr/flagr, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/openflagr/flagr to 0.0.0-20251009103504-fe83dc87aa40 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-0650 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-0650 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-0650. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
How to detect CVE-2026-0650
A community-maintained Nuclei template exists for this CVE. You can scan for it directly:
nuclei -id cve-2026-0650 -u https://target- Template
- OpenFlagr <= 1.1.18 - Authentication Bypass
- Severity
- critical
- Impact
- Attackers can bypass authentication to modify feature flags and export sensitive data, compromising system integrity and confidentiality.
- Remediation
- Update to the latest version beyond 1.1.18.
Template by ProjectDiscovery nuclei-templates (str4k3r), MIT licensed. View the full template. Scan only systems you are authorised to test.
Frequently Asked Questions
Is CVE-2026-0650 in your dependencies?
O3 Security finds CVE-2026-0650 across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.