Security Digest · Vulnerability record
CVE-2026-0650: OpenFlagr contains an authentication bypass vulnerability in the HTTP middleware
OpenFlagr versions prior to and including 1.1.18 contain an authentication bypass vulnerability in the HTTP middleware.
CVSS 9.3 Critical EPSS 1.5% · p74
Should you act?
Critical and remotely reachable
No known exploitation yet, but it is network-reachable without credentials. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.
- Not in CISA KEV, but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
- EPSS 1.5%, percentile 74: FIRST’s model estimates a 1.5% chance of exploitation activity in the next 30 days, higher than 74% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Only applies if your dependency tree includes
github.com/openflagr/flagr(Go) < 0.0.0-20251009103504-fe83dc87aa40, fixed in 0.0.0-20251009103504-fe83dc87aa40. Check your lockfile, including transitive dependencies.
What it is
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.
From the GitHub advisory
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 type: CWE-306, CWE-425.
Product: github.com/openflagr/flagr (Go) · Assigned by: VulnCheck · Published: 2026-01-07
Affected and fixed versions
| Ecosystem | Package | Vulnerable | First fixed |
|---|---|---|---|
| Go | github.com/openflagr/flagr | < 0.0.0-20251009103504-fe83dc87aa40 | 0.0.0-20251009103504-fe83dc87aa40 |
| Vendor | Product | Affected versions (per CVE record) |
|---|---|---|
| OpenFlagr | Flagr | <= 1.1.18 |
Severity scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| VulnCheck | 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 |
| GitHub | 4.0 | 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 |
- Attack vector: network (remotely reachable)
- Attack complexity: low
- Attack requirements: none
- Privileges required: none (no login)
- User interaction: none
CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.
Exploitation and urgency
- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation poc, automatable yes, technical impact total.
- FIRST EPSS (model of 2026-10-21): 1.52% probability of exploitation activity in the next 30 days; percentile 74.
Timeline
- — CVE record published by VulnCheck
- — GitHub-reviewed advisory GHSA-rwp9-5g7q-73q3 published (critical)
- — CVE record last updated
Sources and references
Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.
Vendor and project advisories, patches
- github.com github.com
Vulnerability records
- GitHub Advisory GHSA-rwp9-5g7q-73q3 github.com
- CVE.org record CVE-2026-0650 cve.org
- NVD entry CVE-2026-0650 nvd.nist.gov
Other references from the CVE record and advisory
- dreyand.rs dreyand.rs
- vulncheck.com vulncheck.com
- github.com github.com