CVE-2026-63198

High

Description

traQ is a messenger application built for Digital Creators Club traP. Prior to 3.28.3, OAuth2 silent authorization requests using prompt=none with an empty or omitted scope parameter check prior consent against the empty requested scope set even though all scopes registered for the client become eligible for issuance. An attacker who controls an OAuth client capable of receiving authorization codes can target a user who previously consented to only some client scopes and obtain an access token containing broader registered scopes without additional consent. A user who has never consented to the client still receives consent_required. This issue is fixed in version 3.28.3.

SeverityHigh
CVSS7.3
Exploit probability—
ProducttraQ
PublishedNov 3, 2026
First seenNov 4, 2026

How to fix

Sources list no fixed version or patch link for this vulnerability.

Affected products

ProductAffected versionsFixed in
traPtitech traQ< 3.28.3—

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CVE-2026-63198 · traQ · Dark Radar