Gwolle Guestbook < 4.2.0 - Reflected Cross-Site Scripting

published 2021-12-27 4 y ago modified 2026-06-17 4 mo ago also EUVD-2021-11892

cvss: 6.1; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 0.8%; EPSS 0.8% chance of exploitation in 30 days, percentile 57%
public exploits: 0; none known

The Gwolle Guestbook WordPress plugin before 4.2.0 does not sanitise and escape the gwolle_gb_user_email parameter before outputting it back in an attribute, leading to a Reflected Cross-Site Scripting issue in an admin page

Patch / fix

fixed in 1

gwolle_guestbook_project gwolle_guestbook 4.2.0

Exploit prediction

0.83% chance of exploitation in the next 30 days, higher than 57% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

wpscan.com https://wpscan.com/vulnerability/e50bcb39-9a01-433f-81b3-fd4018672b85 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

Unknown Gwolle Guestbook

Classification

Weakness

CWE-79 Improper Neutralization of Input During Web Page Generation

Technology feeds

WordPress rss critical rss

References

wpscan.com /vulnerability/e50bcb39-9a01-433f-81b3-fd4018672b85
exploit, third-party-advisory

Sources

CVE List CVE-2021-24980
NVD CVE-2021-24980

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