CVE-2026-18978Network attack vectorHinoki check available

Unauthenticated stored XSS via comment attribute rewriting

Published Aug 28, 2026 · Updated Aug 28, 2026

Stored cross-site scripting in LiteSpeed Cache for WordPress 7.8.1 and earlier allows remote attackers to inject scripts through comments. Its image-optimization path rewrites comment HTML after wp_kses; decimal character references inside an allowed element become a data-settings attribute without adequate output escaping. Exploitation requires WebP or AVIF output and an unmoderated comment path; visiting the affected page runs the stored script in the visitor's browser.

CVSS severityUnavailable
Unscored
EPSS probability0.27%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Stored cross-site scripting in LiteSpeed Cache for WordPress 7.8.1 and earlier allows remote attackers to inject scripts through comments. Its image-optimization path rewrites comment HTML after wp_kses; decimal character references inside an allowed element become a data-settings attribute without adequate output escaping. Exploitation requires WebP or AVIF output and an unmoderated comment path; visiting the affected page runs the stored script in the visitor's browser.

The record

CVE
CVE-2026-18978
Published
Aug 28, 2026
Updated
Aug 28, 2026
Vendor
LiteSpeed Technologies
Product
LiteSpeed Cache for WordPress
Classifications
T1059.007
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 28, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 28, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=7.8.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

LiteSpeed Technologies · LiteSpeed Cache for WordPressversion=0 <=7.8.1

Published CVSS scores

No CVSS assessment is available in this record.

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1059.007Command and Scripting Interpreter: JavaScript/JScript

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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