Vulnerability · Published Nov 3, 2026 · Assigned by GitHub_M

CVE-2026-63197traQ: XSS in the User Uploaded File Retrieval API

High 7.3

In plain English

A high-severity cross-site scripting in traQ from traPtitech. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 21% of all known vulnerabilities).

Severity (CVSS 3.1)7.3High

Exploit odds (30 days)0.3%top 78.7% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

traQ is a messenger application built for Digital Creators Club traP. Prior to 3.28.3, instances configured with TRAQ_STORAGE_TYPE=local can return user-uploaded SVG or HTML content from the /files/{fileId} retrieval endpoint for direct browser rendering. An attacker with file-upload capability can provide crafted active content and induce another user to open its file URL, causing attacker-controlled JavaScript to execute in the victim's browser. This issue is fixed in version 3.28.3.

Affected products (as reported)

Vendor	Product	Versions
traPtitech	traQ	< 3.28.3

Weakness: CWE-79 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N

References

https://github.com/traPtitech/traQ/security/advisories/GHSA-p74g-f95m-7fx7 x_refsource_CONFIRM
https://github.com/traPtitech/traQ/commit/3db29e7771661f6418d88d186d8ff7817f5d6b6e x_refsource_MISC
https://github.com/traPtitech/traQ/releases/tag/v3.28.3 x_refsource_MISC