PostmarkApp Email Integrator <= 2.4 - Authenticated (Administrator+) Stored Cross-Site Scripting via Plugin Settings
Strategic Overview
- Status
- Patched in 2.5.0
- Affected Plugin
- PostmarkApp Email Integrator
- Affected Version
<= 2.4- CVSS
- 4.4Medium
- Weakness type
- CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
- CVE
CVE-2026-1043
At a glance
CVE-2026-1043 is a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the PostmarkApp Email Integrator WordPress plugin, affecting versions <= 2.4. It carries a CVSS score of 4.4 (reachable over the network). Exploitation requires an authenticated account at Administrator level or above. The issue is fixed in version 2.5.0; sites on affected versions should update now. Disclosed February 2026, reported by 0x34rth.
Vulnerability Overview
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.
Technical Analysis
The vector marks this flaw as remotely reachable over the network, and no interaction from a victim user.
CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Reaching this weakness in PostmarkApp Email Integrator <= 2.4 takes an account at Administrator level or above. Cross-site scripting happens when input from a request is written into a page without being escaped for the context it lands in, so the browser parses attacker-supplied text as markup or script.
Injected script runs with the privileges of whoever views the affected page, which is how these flaws turn into administrator session theft, silent account creation or persistent backdoors in page content. For PostmarkApp Email Integrator the fix is 2.5.0: builds <= 2.4 are affected, anything from 2.5.0 onward is not.
Remediation
Update to version 2.5.0, or a newer patched version
How does WordSec protect against this?
An attacker needs Administrator access first, so the firewall sees the attempt as traffic from a logged-in account: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: PostmarkApp Email Integrator 2.5.0 closes this, and updating the plugin is the step that ends it.
- Firewall
- Alerts
External References
Related records
Other vulnerabilities in PostmarkApp Email Integrator
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