Speed Optimizer <= 7.8.0 - Authenticated (Contributor+) Stored Cross-Site Scripting via Image Tag Attributes
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Cross-site scripting
- Confidentiality · integrity · availability
- Low · Low · None
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-79.
Summary
The Speed Optimizer – The All-In-One Performance-Boosting Plugin plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Image Tag Attributes in all versions up to, and including, 7.8.0 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This is only exploitable when the site administrator has enabled the Lazy Load Media option in the plugin settings.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| SiteGround | Speed Optimizer – The All-In-One Performance-Boosting Plugin | up to 7.8.0 | — | No fix listed | CNA |
- Speed Optimizer – The All-In-One Performance-Boosting Plugin VendorSiteGround Affected up to 7.8.0 Fixed in — No fix listed CNA
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2026-15421
- 2026-10-03 Alias added: GHSA-8r64-rxjj-mp32
References
Other 9
- https://www.wordfence.com/threat-intel/vulnerabilities/id/2626ad96-4346-4564-b6bd-0c226bd8dfd4?source=cve
- https://plugins.trac.wordpress.org/browser/sg-cachepress/tags/7.8.0/core/Lazy_Load/Lazy_Load_Images.php#L31
- https://plugins.trac.wordpress.org/browser/sg-cachepress/tags/7.8.0/core/Lazy_Load/Abstract_Lazy_Load.php#L109
- https://plugins.trac.wordpress.org/browser/sg-cachepress/tags/7.8.0/core/Lazy_Load/Lazy_Load.php#L39
- https://plugins.trac.wordpress.org/browser/sg-cachepress/tags/7.7.11/core/Lazy_Load/Lazy_Load_Images.php#L31
- https://plugins.trac.wordpress.org/browser/sg-cachepress/tags/7.7.11/core/Lazy_Load/Abstract_Lazy_Load.php#L109
- https://plugins.trac.wordpress.org/browser/sg-cachepress/tags/7.7.11/core/Lazy_Load/Lazy_Load.php#L39
- https://plugins.trac.wordpress.org/changeset?reponame=&new=3642965%40sg-cachepress%2Ftags%2F7.8.1&old=3581843%40sg-cachepress%2Ftags%2F7.8.0
- https://plugins.trac.wordpress.org/changeset?old_path=%2Fsg-cachepress/tags/7.8.0&new_path=%2Fsg-cachepress/tags/7.8.1
More SiteGround vulnerabilities
- TI-2022-00891 SiteGround Security <= 1.2.5 - Authentication Bypass via 2FA Setup CVSS 3.1CRITICAL 9.8
- TI-2022-00892 SiteGround Security <= 1.2.5 - Authorization Weakness to Authentication Bypass CVSS 3.1CRITICAL 9.8
- TI-2023-00224 SiteGround Security < 1.3.1 - Admin+ SQLi CVSS 3.1HIGH 8.8
- TI-2019-15271 SiteGround Optimizer <= 5.0.12 - Missing Authorization CVSS 3.1CRITICAL 9.8
- TI-2026-56695 WordPress SiteGround Security plugin <= 1.6.6 - 2FA Bypass vulnerability CVSS 3.1HIGH 8.1
- TI-2026-41353 WordPress SiteGround Email Marketing plugin <= 1.7.5 - Cross Site Scripting (XSS) vulnerability CVSS 3.1HIGH 7.1
Sources
- CVE-2026-15421 · CVE Program
- CVE-2026-15421 · NVD
- FIRST EPSS
- GHSA-8r64-rxjj-mp32 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences