CVE-2026-25529 Postal has HTML injection / XSS in message view
Attackers can inject arbitrary HTML and JavaScript into the Postal admin interface via the send/raw API, potentially executing unauthorized scripts.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-25529?
CVE-2026-25529 is a high-severity cross-site scripting vulnerability in postalserver postal, published on 12 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Postal is an open source SMTP server. Postal versions less than 3.3.5 had a HTML injection vulnerability that allowed unescaped data to be included in the admin interface. The primary way for unescaped data to be added is via the API's "send/raw" method. This could allow arbitrary HTML to be injected in to the page which may modify the page in a misleading way or allow for unauthorised javascript to be executed. Fixed in 3.3.5 and higher.
Weakness: CWE-79
Which versions are affected by CVE-2026-25529?
It affects 1 product.
Products include Postalserver Postal.
How do I fix CVE-2026-25529?
No fix has been published for CVE-2026-25529 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-25529 being exploited?
There is no known exploitation of CVE-2026-25529 in the wild and no public exploit code.
Other vulnerabilities in postalserver postal
Sources
Also known as GHSA-5f4r-5jpr-rfhc.