CVE-2026-11443 Allegra downloadAttachment Cross-Site Scripting Authentication Bypass Vulnerability
Remote attackers can execute arbitrary script in the context of the current user via the downloadAttachment method, potentially leading to account takeover.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-11443?
CVE-2026-11443 is a medium-severity cross-site scripting vulnerability in Allegra, published on 12 Jun 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
Allegra downloadAttachment Cross-Site Scripting Authentication Bypass Vulnerability. This vulnerability allows remote attackers to execute arbitrary script on affected installations of Allegra. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file.
The specific flaw exists within the downloadAttachment method. The issue results from the lack of proper validation of user-supplied data, which can lead to the injection of arbitrary script. An attacker can leverage this vulnerability to execute script in the context of the current user. Was ZDI-CAN-28236.
Weakness: CWE-79
Which versions are affected by CVE-2026-11443?
How do I fix CVE-2026-11443?
No fix has been published for CVE-2026-11443 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-2026-11443 being exploited?
There is no known exploitation of CVE-2026-11443 in the wild and no public exploit code.
Sources
Also known as GHSA-m8wq-7mhg-mgm7.