What is CVE-2021-24288?

CVE-2021-24288 is a medium-severity vulnerability in Acymailing, classified under URL Redirection to Untrusted Site (Open Redirect). CVSS score: 6.1/10. Published 2021-05-17.

How severe is CVE-2021-24288?

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

Is CVE-2021-24288 known to be exploited?

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

Open Redirect in Acymailing

CVE-2021-24288

When subscribing using AcyMailing, the 'redirect' parameter isn't properly sanitized. Turning the request from POST to GET, an attacker can craft a link containing a potentially malicious landing page and send it to the victim.

Vulnerability class: Open Redirect

Published 2021-05-17 · 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: 0.019 (79.3th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 79th percentile — 79.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.019 · newest: 0.019 · change: 0.000

Affected products

Acymailing
Acymailing Newsletter Via Smtp, Sendinblue, Sendgrid, Mailgun - Smtp — versions 7.5.0

Weakness classification (CWE)

CWE-601 — URL Redirection to Untrusted Site (Open Redirect)

Public proof-of-concept exploits

References

wpscan.com/vulnerability/56628862-1687-4862-9ed4-145d8dfbca97 (Exploit, Third Party Advisory)

Frequently asked questions

What is CVE-2021-24288?: CVE-2021-24288 is a medium-severity vulnerability in Acymailing, classified under URL Redirection to Untrusted Site (Open Redirect). CVSS score: 6.1/10. Published 2021-05-17.
How severe is CVE-2021-24288?: Medium severity. CVSS v3 base score is 6.1 out of 10.
Is CVE-2021-24288 known to be exploited?: 3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.