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Vulnerabilities

Vulnerability · CVE-2025-66121

Missing Authorization vulnerability in SiteGround SiteGround Security sg-security allows Exploiting Incorrectly Configured Access Control Security Levels.This issue affects SiteGro

Published Dec 16, 2025 · catalog updated Apr 28, 2026 · SiteGround SiteGround Security

Last checked Nov 2, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2025-66121. EPSS is 0.32%. Act only if a listed version of SiteGround SiteGround Security is installed.

Gaps on this record

  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
Medium5.3
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.32%
Remediation
Advisory link
Affected products
vendor SiteGround SiteGround Security 0 ≤1.5.8

Missing Authorization vulnerability in SiteGround SiteGround Security sg-security allows Exploiting Incorrectly Configured Access Control Security Levels.This issue affects SiteGround Security: from n/a through <= 1.5.8.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • vendor SiteGround SiteGround Security 0 ≤1.5.80 ≤1.5.8

How to fix CVE-2025-66121

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2025-66121. EPSS is 0.32%. Act only if a listed version of SiteGround SiteGround Security is installed.

Which versions are affected?

Compare what you have installed with SiteGround SiteGround Security 0 ≤1.5.8 0 ≤1.5.8. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

No weakness class is stored. EPSS 0.32%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Dec 16, 2025 · EUVD

    Detected

    Missing Authorization vulnerability in SiteGround SiteGround Security sg-security allows Exploiting Incorrectly Configured Access Control Security Levels.This issue affects SiteGround Security: from n/a through <= 1.5.8.

  2. Apr 28, 2026 · EUVD

    Updated

    Missing Authorization vulnerability in SiteGround SiteGround Security sg-security allows Exploiting Incorrectly Configured Access Control Security Levels.This issue affects SiteGround Security: from n/a through <= 1.5.8.

Sources

  • CVE.orgVulnerability recordCVE-2025-66121

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2025-66121

    30-day exploitation probability 0.32%

    first.org
  • EUVDVulnerability recordEUVD-2025-203588

    Missing Authorization vulnerability in SiteGround SiteGround Security sg-security allows Exploiting Incorrectly Configured Access Control Security Levels.This issue affects SiteGround Security: from n/a through <= 1.5.8.

    euvd.enisa.europa.eu

References

Freshness

Last verified in this catalog Nov 2, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

  • FIRST EPSSNov 2, 2026
  • CVE.orgOct 29, 2026
  • EUVDOct 29, 2026