Stored XSS in Cervantes Product by Grayback
CVE-2026-129427

8.7HIGH

Key Information:

Vendor

Cervantessec

Status
Cervantes
Vendor
CVE Published:
14 November 2026

What is CVE-2026-129427?

A vulnerability exists within Cervantes that enables stored XSS through avatar uploads, which, when combined with an authentication bypass in the /Attachments endpoint, could allow an attacker to execute arbitrary code in a victim's browser with escalated permissions, potentially leading to account takeover.

Affected Version(s)

cervantes alpha 0.3 <= 1.3-beta

cervantes v.1.4.0-beta

References

https://www.grayback.es/advisories
patch
https://www.grayback.es/en/advisories
patch

CVSS V3.1

Score:
8.7
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
Required
Scope:
Changed

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Miguel Segovia Gil
.