LiteSpeed Cache <= 7.9 — Reflected Cross-Site Scripting via ESI 'esi' Parameter
CVE-2026-76579Published · Updated Action summary
Affected: ≤7.9Update to 7.9.1 or newer
All remediation steps- Severity
- Medium4.7
- CVSS
- 4.7CVSS 3.1 · CNA (Wordfence)
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:NWhat does this vector mean?
AV:NAttack vector- Network
AC:HAttack complexity- High
PR:NPrivileges required- None
UI:RUser interaction- Required
S:CScope- Changed
C:LConfidentiality- Low
I:LIntegrity- Low
A:NAvailability- None
- Weakness
- CWE-79 Cross-Site Scripting
- Required access
- No account needed
- Exploit prediction (EPSS)
- 0.4% chance in 30 days32th percentile
- CISA KEV
- Not listed
On this page8
Am I affected?
LiteSpeed Cache litespeed-cache
- Affected≤ 7.9
- Patched in7.9.1
Update to 7.9.1 or newer.
You are affected if you run ≤ 7.9. Version 7.9.1 and later are not affected by this issue.
- Check your version: in wp-admin go to Plugins → Installed Plugins and read the version under LiteSpeed Cache.
- No admin access? Run a passive check of your site. It reads public files only.
- No account is needed to exploit this. Treat any exposed site on an affected version as at risk.
What to do
- Update to version 7.9.1, or a newer patched version
- Rotate administrator passwords and application secrets if the site ran a vulnerable version while publicly reachable.
- Watch LiteSpeed Cache to get an email when the next vulnerability is published.
Advisory
Source description from Wordfence Intelligence, credited to mak3bread.
The LiteSpeed Cache plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via the 'esi' parameter in all versions up to, and including, 7.9 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a link. Exploitation requires that the attacker supply a validly signed 'esi' value in the GET query string while submitting a separate attacker-controlled 'esi' payload as a POST body field, relying on PHP's default $_REQUEST merge order to have the POST value take precedence at the point of execution.
Exploits & references
Proof-of-concept & detection
No public proof-of-concept or detection template is known for this vulnerability.
Advisories & patches
- Advisorywordfence.com
Related CVEs
More in LiteSpeed Cache
All 30| Severity | Vulnerability | CVE | Published |
|---|---|---|---|
| High8.2 | Unauthenticated Sensitive Information Disclosure (WooCommerce Store API Cart/Checkout PII + Cart-Token) via Public REST Caching ≤7.9.1Update to 7.9.2 | CVE-2026-93389 | |
| Medium6.4 | Authenticated (Subscriber+) Stored Cross-Site Scripting via VPI Image Attribute Re-Serialization ≤7.9.1Update to 7.9.2 | CVE-2026-109215 | |
| Medium5.4 | Unauthenticated Stored Cross-Site Scripting via HTML Minifier Predictable Placeholder (md5(REQUEST_TIME) + two-pass str_replace) ≤7.9.1Update to 7.9.2 | CVE-2026-116763 | |
| High7.2 | Unauthenticated Stored Cross-Site Scripting <7.9.2Update to 7.9.2 | CVE-2026-113499 | |
| High7.2 | Unauthenticated Stored Cross-Site Scripting <7.9.2Update to 7.9.2 | CVE-2026-113500 |
- High8.2Unauthenticated Sensitive Information Disclosure (WooCommerce Store API Cart/Checkout PII + Cart-Token) via Public REST Caching
≤7.9.1Update to 7.9.2
- Medium6.4Authenticated (Subscriber+) Stored Cross-Site Scripting via VPI Image Attribute Re-Serialization
≤7.9.1Update to 7.9.2
- Medium5.4Unauthenticated Stored Cross-Site Scripting via HTML Minifier Predictable Placeholder (md5(REQUEST_TIME) + two-pass str_replace)
≤7.9.1Update to 7.9.2
- High7.2Unauthenticated Stored Cross-Site Scripting
<7.9.2Update to 7.9.2
- High7.2Unauthenticated Stored Cross-Site Scripting
<7.9.2Update to 7.9.2
Same weakness (Cross-Site Scripting)
All Cross-Site Scripting| Severity | Vulnerability | CVE | Published |
|---|---|---|---|
| High7.2 | Unauthenticated Stored Cross-Site Scripting via Comment User-Agent Header | CVE-2026-120688 | |
| Critical9.8 | Unauthenticated Arbitrary File Upload via File Upload via Public Form Submission | CVE-2026-125055 | |
| Critical9.8 | Unauthenticated PHP Object Injection to Remote Code Execution via 'form' Parameter | CVE-2026-119077 | |
| Medium5.3 | Unauthenticated Sensitive Information Exposure in 'search' Parameter | CVE-2026-121518 |
- High7.2Unauthenticated Stored Cross-Site Scripting via Comment User-Agent Header
EZ SQL Reports Shortcode Widget and DB Backup
≤5.25.25Update to 5.26.45
- Critical9.8Unauthenticated Arbitrary File Upload via File Upload via Public Form Submission
Chatterbug Forms – Fast, Flexible WordPress Form Builder
≤1.0.2Update to 1.1
- Critical9.8Unauthenticated PHP Object Injection to Remote Code Execution via 'form' Parameter
ELEX WordPress HelpDesk & Customer Ticketing System
≤3.3.9Update to 3.4.0
- Medium5.3Unauthenticated Sensitive Information Exposure in 'search' Parameter
Customer Reviews for WooCommerce
≤5.127.0Update to 5.128.0
Timeline
CVE published
Severity medium, CVSS 4.7
Record last updated
Sources & licenses
Wordfence record- Vulnerability data
- Wordfence Intelligence. Copyright 2012-2026 Defiant Inc. Licensed under the CC BY-SA 4.0.
- CVE® identifiers
- Copyright 1999-2026 The MITRE Corporation. Used under the CVE Program. CVE® is a registered trademark of The MITRE Corporation.
- CVSS / CWE
- National Vulnerability Database (NVD), shown unmodified. This product uses the NVD API but is not endorsed or certified by the NVD.
- EPSS
- Exploit Prediction Scoring System by FIRST.org.
- VulnCrest content
- Summary, remediation guidance and page layout © VulnCrest. Not sourced from NVD.