CVE-2026-15421 (GCVE-0-2026-15421)
Vulnerability from cvelistv5 – Published: 2026-08-19 01:26 – Updated: 2026-08-19 01:26
VLAI
EPSS
VEX
Title
Speed Optimizer <= 7.8.0 - Authenticated (Contributor+) Stored Cross-Site Scripting via Image Tag Attributes
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.
Severity
6.4 (Medium)
CWE
- CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Assigner
References
9 references
Impacted products
1 product
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| siteground | Speed Optimizer – The All-In-One Performance-Boosting Plugin |
Affected:
0 , ≤ 7.8.0
(semver)
|
guessed |
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"vendor": "siteground",
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}
],
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"problemTypes": [
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"description": "CWE-79 Improper Neutralization of Input During Web Page Generation (\u0027Cross-site Scripting\u0027)",
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"providerMetadata": {
"dateUpdated": "2026-08-19T01:26:11.381Z",
"orgId": "b15e7b5b-3da4-40ae-a43c-f7aa60e62599",
"shortName": "Wordfence"
},
"references": [
{
"url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/2626ad96-4346-4564-b6bd-0c226bd8dfd4?source=cve"
},
{
"url": "https://plugins.trac.wordpress.org/browser/sg-cachepress/tags/7.8.0/core/Lazy_Load/Lazy_Load_Images.php#L31"
},
{
"url": "https://plugins.trac.wordpress.org/browser/sg-cachepress/tags/7.8.0/core/Lazy_Load/Abstract_Lazy_Load.php#L109"
},
{
"url": "https://plugins.trac.wordpress.org/browser/sg-cachepress/tags/7.8.0/core/Lazy_Load/Lazy_Load.php#L39"
},
{
"url": "https://plugins.trac.wordpress.org/browser/sg-cachepress/tags/7.7.11/core/Lazy_Load/Lazy_Load_Images.php#L31"
},
{
"url": "https://plugins.trac.wordpress.org/browser/sg-cachepress/tags/7.7.11/core/Lazy_Load/Abstract_Lazy_Load.php#L109"
},
{
"url": "https://plugins.trac.wordpress.org/browser/sg-cachepress/tags/7.7.11/core/Lazy_Load/Lazy_Load.php#L39"
},
{
"url": "https://plugins.trac.wordpress.org/changeset?reponame=\u0026new=3642965%40sg-cachepress%2Ftags%2F7.8.1\u0026old=3581843%40sg-cachepress%2Ftags%2F7.8.0"
},
{
"url": "https://plugins.trac.wordpress.org/changeset?old_path=%2Fsg-cachepress/tags/7.8.0\u0026new_path=%2Fsg-cachepress/tags/7.8.1"
}
],
"timeline": [
{
"lang": "en",
"time": "2026-08-18T13:17:17.000Z",
"value": "Disclosed"
}
],
"title": "Speed Optimizer \u003c= 7.8.0 - Authenticated (Contributor+) Stored Cross-Site Scripting via Image Tag Attributes"
}
},
"cveMetadata": {
"assignerOrgId": "b15e7b5b-3da4-40ae-a43c-f7aa60e62599",
"assignerShortName": "Wordfence",
"cveId": "CVE-2026-15421",
"datePublished": "2026-08-19T01:26:11.381Z",
"dateReserved": "2026-07-10T15:11:57.894Z",
"dateUpdated": "2026-08-19T01:26:11.381Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
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}
}
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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