SiteGround Security permits unauthenticated two-factor authentication bypass
SiteGround Security through 1.6.6 permits an unauthenticated attacker to bypass its two-factor authentication protection under a higher-complexity condition. Successful exploitation can compromise the confidentiality, integrity and availability of the affected account and site.
- Component
- SiteGround Security
- Plugin slug
sg-security- Affected
- n/a through 1.6.6
- Safe version
1.6.7- Published
- Aug 31, 2026
This CVE was published Aug 31, 2026 and is one of 4 known issues for this plugin.
Update, patch or deactivate.
Update SiteGround Security to 1.6.7 or later, invalidate suspicious sessions, and review authentication and administrator activity.
A safe version is available, so updating to that version or later is the preferred remediation. If an immediate update is not practical, consider a targeted application patch or temporarily restricting the affected functionality.
Deactivate only when warranted by your risk profile, or when advised by your hosting provider in the limited circumstances where the vulnerability cannot otherwise be mitigated. If you’re unsure which action is appropriate, contact Fused or your hosting provider for guidance.
Technical description
Unauthenticated Bypass Vulnerability in SiteGround Security <= 1.6.6 versions.
CVE / CNA vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H