A retest is a follow-up verification step used after a security issue has been fixed. In penetration testing and vulnerability management, the tester repeats the relevant check to confirm that the original weakness is no longer exploitable and that the remediation did not leave a similar path open. A retest is more than a second look: it is evidence that the control or patch actually changed the system’s security state.
Retesting matters because many findings are only partly fixed. A patch may remove one attack path but leave an alternate input, misconfiguration, or privilege issue in place. In real defenses, retests help teams validate closure, reduce repeat findings, and avoid treating an unverified fix as resolved. In attack work, defenders may also retest hardening after incident response or configuration changes to make sure exposed services, credentials, or permissions no longer support abuse. A good retest uses the same scope and methodology as the original finding so the comparison is trustworthy.