CVE-2026-129427

HIGH 8.7

Stored XSS via avatar upload chained with an authentication bypass in /Attachments leads to ATO

CVSS Score

8.7

EPSS Score

0.0%

EPSS Percentile

0th

Stored XSS via avatar upload chained with an authentication bypass in /Attachments leads to ATO in Cervantes version v1.3-beta could allow an attacker to execute arbitrary code in another user's browser with elevated privileges

CWE	CWE-79
Vendor	cervantessec
Product	cervantes
Published	Nov 14, 2026

Stay Ahead of the Next One

Get instant alerts for cervantessec cervantes

Be the first to know when new high vulnerabilities affecting cervantessec cervantes are published — delivered to Slack, Telegram or Discord.

Get Free Alerts → Free · No credit card · 60 sec setup

CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

Required

Scope

Changed

Confidentiality

High

Integrity

High

Availability

None

Affected Versions

CervantesSec / cervantes

alpha 0.3 ≤ 1.3-beta

References

NVD ↗ CVE.org ↗ EPSS Data ↗

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

Credits

Miguel Segovia Gil