ZDI-26-358: 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 ZDI has assigned a CVSS rating of 4.6. The following CVEs are assigned: CVE-2026-11443.
AI Analysis
Technical Summary
The Allegra downloadAttachment method improperly validates user-supplied data, enabling remote attackers to inject and execute arbitrary scripts in the context of the current user. Exploitation requires user interaction, such as visiting a malicious webpage or opening a malicious file. This vulnerability is tracked as CVE-2026-11443 and was publicly disclosed by the Zero Day Initiative on June 11, 2026. Allegra has released an update to fix this issue as detailed in their release notes for version 9.0.0.
Potential Impact
Successful exploitation allows remote attackers to execute arbitrary scripts within the context of the affected user's session, potentially leading to information disclosure or session hijacking. The vulnerability requires user interaction and has a CVSS base score of 4.6, reflecting limited impact and exploit complexity.
Mitigation Recommendations
Allegra has issued an official update that corrects this vulnerability. Users and administrators should apply the update as described in Allegra's release notes for version 9.0.0 to remediate this issue. No additional mitigation steps are indicated by the vendor advisory.
ZDI-26-358: Allegra downloadAttachment Cross-Site Scripting Authentication Bypass Vulnerability
Description
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 ZDI has assigned a CVSS rating of 4.6. The following CVEs are assigned: CVE-2026-11443.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The Allegra downloadAttachment method improperly validates user-supplied data, enabling remote attackers to inject and execute arbitrary scripts in the context of the current user. Exploitation requires user interaction, such as visiting a malicious webpage or opening a malicious file. This vulnerability is tracked as CVE-2026-11443 and was publicly disclosed by the Zero Day Initiative on June 11, 2026. Allegra has released an update to fix this issue as detailed in their release notes for version 9.0.0.
Potential Impact
Successful exploitation allows remote attackers to execute arbitrary scripts within the context of the affected user's session, potentially leading to information disclosure or session hijacking. The vulnerability requires user interaction and has a CVSS base score of 4.6, reflecting limited impact and exploit complexity.
Mitigation Recommendations
Allegra has issued an official update that corrects this vulnerability. Users and administrators should apply the update as described in Allegra's release notes for version 9.0.0 to remediate this issue. No additional mitigation steps are indicated by the vendor advisory.
Threat ID: 6a2bf5b8e617e2d83464941d
Added to database: 06/12/2026, 12:04:08 UTC
Last enriched: 07/06/2026, 00:43:39 UTC
Last updated: 07/19/2026, 05:26:45 UTC
Views: 81
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