Skip to main content
No exploitation reportedAwaiting NVD analysis

CVE-2026-126800

Hydro @hydrooj/ui-default before 4.59.1 Stored XSS via Markdown language- Class

No exploitation reported by the sources we read.

  • Published2026-11-11
  • WeaknessCWE-79

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

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.

Timeline

dates in UTC
  1. 2026-11-1120:53CVE publishedCNA

Versions per branch

Products declared by the CNA

As VulnCheck, the CNA that assigned this CVE, declared them in the CVE record; versions as written. NVD lists no product for this CVE yet: this is the only product data so far.

  • hydro-dev @hydrooj/ui-defaultother versions: not affected
    Affected
    • < 4.59.1fixed in 4.59.1semver

Source: the CNA record (CVE Program), © The MITRE Corporation,CVE Terms of UseCVE recordupdated 2026-11-11

Neither OSV.dev nor the vendor advisories we read list affected versions for CVE-2026-126800 yet.

Full record on NVD

Fix

No fix published by the sources we read yet. NVD record

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Metasploit modules
none listed
Metasploit Framework

Sources

  • CNACVSS 4.09.32026-11-11
  • CNACVSS 3.18.72026-11-11
  • NVDCVSS 3.18.7read 2026-11-11
  • CNAweakness (CWE)CWE-792026-11-11
  • NVDweakness (CWE)CWE-79read 2026-11-11

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N
CVSS 4.0 vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Published
2026-11-11
Last Modified
2026-11-11
NVD status
Received

Frequently asked questions

What is CVE-2026-126800?

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.

Is CVE-2026-126800 actively exploited?

Active exploitation of CVE-2026-126800 has not been confirmed.

What is the CVSS score for CVE-2026-126800?

CVE-2026-126800 has a CVSS v3 base score of 8.7 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N.

Hear about the next vulnerability in your software

Surveillance reads the versions in your stack — a domain, a lockfile or a list — checks each CVE against the ranges its sources publish, and alerts you when one you run is exploited or enters CISA KEV. A version it cannot read stays « version not verified ».

Get alerts for this productCISA KEV additions, November 2026Search CVEs

No credit card required · No monthly cap on website lookups · 250 API requests/month

Go further

Related vulnerabilities

Same product first, then the same vendor advisory and the same publication week.

Back to CVE Database

Sources for this record