CVE-2026-126800
Hydro @hydrooj/ui-default before 4.59.1 Stored XSS via Markdown language- Class
Description
Hydro @hydrooj/ui-default before 4.59.1 contains a stored cross-site scripting vulnerability that allows registered users to inject script by placing double quotes in language- class tokens within markdown-it-xss.ts. Attackers can store a payload in their profile bio that executes when administrators or other users view it, stealing the non-httpOnly sid session cookie for session hijacking.
INFO
Published Date :
Nov. 11, 2026, 8:53 p.m.
Last Modified :
Nov. 11, 2026, 8:53 p.m.
Remotely Exploit :
Yes !
Source :
VulnCheck
Affected Products
The following products are affected by CVE-2026-126800
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 4.0 | CRITICAL | 83251b91-4cc7-4094-a5c7-464a1b83ea10 |
Solution
- Update Hydro @hydrooj/ui-default to version 4.59.1 or later.
- Sanitize user input in profile bio and markdown processing.
- Implement robust input validation for language-class tokens.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-126800 vulnerability anywhere in the article.