XSS in Gagan0123 Postmarkapp Email Integrator

CVE-2026-1043

The PostmarkApp Email Integrator plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin settings in versions up to, and including, 2.4. This is due to insufficient input sanitization and output escaping on the pma_api_key and pma_sender_address parameters. This makes it possible for authenticated attackers, with Administrator-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses the settings page.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 4.4 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.003 (15.4th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 15th percentile — 15.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-1043: held from 0.002 to 0.003.

EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-1043?
CVE-2026-1043 is a medium-severity vulnerability in Gagan0123 Postmarkapp Email Integrator, classified under Cross-site Scripting. CVSS score: 4.4/10. Published 2026-02-19.
How severe is CVE-2026-1043?
Medium severity. CVSS v3 base score is 4.4 out of 10.