CVE-2026-11443: Allegra downloadAttachment Cross-Site Scripting Authentication Bypass Vulnerability. This vulnerability allows remote attackers to execute arbitrary s...

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.

Metrics

CVSS 3.0

4.6/10

CVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N

EPSS Probability

0.22%

13.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-79

References

Timeline

Published: Jun 13, 2026
Last Modified: Jun 17, 2026
Status: Deferred

Frequently Asked Questions

What is CVE-2026-11443?

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.

How severe is CVE-2026-11443?

CVE-2026-11443 has a CVSS score of 4.6/10 (MEDIUM severity). The EPSS model estimates a 0.22% probability of exploitation in the next 30 days.

How do I fix CVE-2026-11443?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.