Stored XSS via avatar upload chained with an authentication bypass in /Attachments leads to ATO in Cervantes version
Source GCVE Database
Not known to be exploited · CVSS 8.7 High.
Data as of 14 Nov 2026, 13:17 UTC
Thin evidence
One scorer or none| CNA (Grayback) | CVSS 3.1 | 8.7 |
|---|
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:NExploitation evidence
Disclosed: evidence found.
CVE published 14 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 14 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| CervantesSeccervantes | Affected
| Fixed in– |
AI-suggested
Until a fix is available, restrict avatar upload functionality and monitor for suspicious activity related to /Attachments endpoint. Apply strict input validation and sanitization on avatar uploads and authentication mechanisms as temporary mitigations.
Description
Cervantes version v1.3-beta contains a stored cross-site scripting (XSS) vulnerability via avatar upload combined with an authentication bypass in the /Attachments endpoint. This flaw could allow an attacker to execute arbitrary code in another user's browser with elevated privileges, potentially leading to account takeover (ATO). The vulnerability has a high severity rating with a CVSS score of 8.7.