W3 Total Cache < 2.1.4 - Reflected XSS in Extensions Page (Attribute Context)

published 2021-07-19 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-11348

cvss: 6.1; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 1.8%; EPSS 1.8% chance of exploitation in 30 days, percentile 79%
public exploits: 0; none known, plus a Nuclei check

The W3 Total Cache WordPress plugin before 2.1.4 was vulnerable to a reflected Cross-Site Scripting (XSS) security vulnerability within the "extension" parameter in the Extensions dashboard, which is output in an attribute without being escaped first. This could allow an attacker, who can convince an authenticated admin into clicking a link, to run malicious JavaScript within the user's web browser, which could lead to full site compromise.

Patch / fix

fixed in 1

boldgrid w3_total_cache 2.1.4

Exploit prediction

1.83% chance of exploitation in the next 30 days, higher than 79% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

Nuclei template WordPress W3 Total Cache <2.1.4 - Cross-Site Scripting nuclei detection template
wpscan.com https://wpscan.com/vulnerability/05988ebb-7378-4a3a-9d2d-30f8f58fe9ef referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
NVD	3.1	6.1	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
NVD	2.0	4.3	AV:N/AC:M/Au:N/C:N/I:P/A:N

Affected products

BoldGrid W3 Total Cache

Classification

Weakness

CWE-79 Improper Neutralization of Input During Web Page Generation

Technology feeds

WordPress rss critical rss

References

wpscan.com /vulnerability/05988ebb-7378-4a3a-9d2d-30f8f58fe9ef
exploit, third-party-advisory

Sources

CVE List CVE-2021-24436
NVD CVE-2021-24436

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary