CVE-2026-49864

wetty vulnerable to DOM XSS via file-download filename

Published Aug 13, 2026 CVSS 4.0 · 8.6 High EPSS < 1% KEV · Not listed
Description
wetty provides terminal access in browser over http/https. Prior to version 3.0.4, the wetty client decodes a base64 filename from the file-download escape sequence and interpolates it raw into a Toastify HTML string (`escapeMarkup: false`). Any output the victim renders - a `cat`'d file, a tailed log, an SSH MOTD, a `curl` response - that contains `\x1b[5i...:...\x1b[4i` runs script in the wetty origin and types attacker-chosen keystrokes into the victim's SSH session. Version 3.0.4 fixes the issue.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-p26j-h7wj-r568 wetty vulnerable to DOM XSS via file-download filename
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Butlerx
Butlerx wetty
Vendors & Products Butlerx
Butlerx wetty
Type Values Removed Values Added
Description wetty provides terminal access in browser over http/https. Prior to version 3.0.4, the wetty client decodes a base64 filename from the file-download escape sequence and interpolates it raw into a Toastify HTML string (`escapeMarkup: false`). Any output the victim renders - a `cat`'d file, a tailed log, an SSH MOTD, a `curl` response - that contains `\x1b[5i...:...\x1b[4i` runs script in the wetty origin and types attacker-chosen keystrokes into the victim's SSH session. Version 3.0.4 fixes the issue.
Title wetty vulnerable to DOM XSS via file-download filename
Weaknesses CWE-79
References
Metrics cvssV4_0

{'score': 8.6, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Aug 18, 2026, 1:35 AM
Reserved
Jun 1, 2026, 10:03 PM
Status
Deferred
Published
Aug 13, 2026, 8:17 PM
Modified
Sep 9, 2026, 9:02 PM