How severe is CVE-2021-24556?

CVE-2021-24556 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2021-24556 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (68th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-24556?

CVE-2021-24556 affects Email-subscriber Project Email-subscriber. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-24556?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-24556 published?

CVE-2021-24556 was published on 2021-08-23 and last updated on 2026-06-17.

CVE-2021-24556

CVE-2021-24556 is a medium-severity vulnerability in Email-subscriber Project Email-subscriber with a CVSS 3.x base score of 6.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.

Key facts

Severity: Medium (CVSS 3.x base score 6.1)
CVSS v2: 4.3
EPSS exploit prediction: 1% (68th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Email-subscriber Project Email-subscriber
Published: 2021-08-23
Last modified: 2026-06-17

Description

The kento_email_subscriber_ajax AJAX action of the Email Subscriber WordPress plugin through 1.1, does not properly sanitise, validate and escape the submitted subscribe_email and subscribe_name POST parameters, inserting them in the DB and then outputting them back in the Subscriber list (/wp-admin/edit.php?post_type=kes_campaign&page=kento_email_subscriber_list_settings), leading a Stored XSS issue.

Frequently asked questions

What is CVE-2021-24556?: The kento_email_subscriber_ajax AJAX action of the Email Subscriber WordPress plugin through 1.1, does not properly sanitise, validate and escape the submitted subscribe_email and subscribe_name POST parameters, inserting them in the DB and then outputting them back in the Subscriber list (/wp-admin/edit.php?post_type=kes_campaign&page=kento_email_subscriber_list_settings), leading a Stored XSS issue.
How severe is CVE-2021-24556?: CVE-2021-24556 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2021-24556 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (68th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-24556?: CVE-2021-24556 affects Email-subscriber Project Email-subscriber. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-24556?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-24556 published?: CVE-2021-24556 was published on 2021-08-23 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:email-subscriber_project:email-subscriber:*:*:*:*:*:wordpress:*:*

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