Improper Authentication vulnerabilities
CWE-287 · 12 tracked
Improper authentication (CWE-287) is a flaw where an application fails to correctly verify a user’s identity, letting an attacker act as another user or bypass login entirely.
How it’s exploited
Depending on the bug: guessing or replaying weak tokens, exploiting a logic flaw in the login flow, or abusing a missing check on a sensitive endpoint — all resulting in access without valid credentials.
How to prevent it
Use vetted authentication libraries, enforce MFA on sensitive access, verify authentication on every protected route (not just the login page), and never roll your own session logic.
Tracked improper authentication vulnerabilities
12 CVEs in this class, each with severity, exploit status, EPSS, and remediation.
CVE-2026-71326CVE-2026-64665CVE-2026-70482CVE-2026-50559CVE-2026-54635CVE-2026-49447GHSA-hp74-gm6m-2qm5GHSA-cmwh-g2h8-c222GHSA-hp6v-6jw7-gv2fCVE-2026-59224GHSA-qq9h-g4jm-xgf3GHSA-r277-6w6q-xmqw
Frequently asked questions
- What is Improper Authentication?
- Improper authentication (CWE-287) is a flaw where an application fails to correctly verify a user’s identity, letting an attacker act as another user or bypass login entirely.
- How is improper authentication exploited?
- Depending on the bug: guessing or replaying weak tokens, exploiting a logic flaw in the login flow, or abusing a missing check on a sensitive endpoint — all resulting in access without valid credentials.
- How do you prevent improper authentication?
- Use vetted authentication libraries, enforce MFA on sensitive access, verify authentication on every protected route (not just the login page), and never roll your own session logic.
- How many improper authentication vulnerabilities are there?
- O3 tracks 12 vulnerabilities classified as CWE-287 (Improper Authentication), each with severity, exploit status, EPSS exploitation probability, and remediation. The full list is below.