Vulnerability · Published Nov 3, 2026 · Assigned by GitHub_M

CVE-2026-63198traQ: Privilege escalation by OAuth prompt=none request

High 7.3

In plain English

A high-severity incorrect authorization 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 17% of all known vulnerabilities).

Severity (CVSS 3.1)7.3High

Exploit odds (30 days)0.3%top 82.8% 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, 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.

Affected products (as reported)

Vendor	Product	Versions
traPtitech	traQ	< 3.28.3

Weakness: CWE-863 · 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-8cfq-jgf7-8m27 x_refsource_CONFIRM
https://github.com/traPtitech/traQ/commit/5510fe8aa9bb15fc4755c78792381dbb03d576c3 x_refsource_MISC
https://github.com/traPtitech/traQ/releases/tag/v3.28.3 x_refsource_MISC