What is CVE-2021-24275?

CVE-2021-24275 is a medium-severity vulnerability in Supsystic Popup, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2021-05-05.

How severe is CVE-2021-24275?

Medium severity. CVSS v3 base score is 6.1 out of 10.

Is CVE-2021-24275 known to be exploited?

3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

XSS in Supsystic Popup

CVE-2021-24275

The Popup by Supsystic WordPress plugin before 1.10.5 did not sanitise the tab parameter of its options page before outputting it in an attribute, leading to a reflected Cross-Site Scripting issue

Vulnerability class: XSS (Cross-Site Scripting)

Published 2021-05-05 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.182 (97.2th percentile), scored 2026-10-20.

Moderate probability of exploitation in the next 30 days — watch for active exploitation reports. 97th percentile — 97.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.182 · newest: 0.182 · change: 0.000

Affected products

Supsystic Popup
Supsystic Popup By — versions 1.10.5

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

Public proof-of-concept exploits

References

wpscan.com/vulnerability/efdc76e0-c14a-4baf-af70-9d381107308f (Exploit, Third Party Advisory)
packetstormsecurity.com/files/164311/WordPress-Popup-1.10.4-Cross-Site-Scriptin… (Exploit, VDB Entry, Third Party Advisory)

Frequently asked questions

What is CVE-2021-24275?: CVE-2021-24275 is a medium-severity vulnerability in Supsystic Popup, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2021-05-05.
How severe is CVE-2021-24275?: Medium severity. CVSS v3 base score is 6.1 out of 10.
Is CVE-2021-24275 known to be exploited?: 3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.