Vulnerability · Published Jun 12, 2026 · Assigned by zdi

CVE-2026-11443Allegra downloadAttachment Cross-Site Scripting Authentication Bypass Vulnerability

Medium 4.6

In plain English

A medium-severity cross-site scripting in Allegra from Allegra. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.8% (higher than 57% of all known vulnerabilities).

Severity (CVSS 3.0)4.6Medium

Exploit odds (30 days)0.8%top 42.6% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

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.

Affected products (as reported)

Vendor	Product	Versions
Allegra	Allegra	8.1.6.22

Weakness: CWE-79 · Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N

References

ZDI-26-358 x_research-advisory
vendor-provided URL vendor-advisory