CVE-2026-63198 is a high-severity (CVSS 7.3) CWE-863 vulnerability. The records list no fixed version yet; check the vendor advisory below and apply the mitigations in the meantime.
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…
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-63198.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
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.
Detection & mitigation playbook
VulnerabilityDetect
Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).
Remediation status
The records we use list no fixed release for CVE-2026-63198. Check the upstream advisory for a patched version, and apply the exposure-reduction steps below in the meantime.
Mitigate without a patch
Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.
Frequently Asked Questions
Is CVE-2026-63198 in your dependencies?
Find it across your dependency tree, including transitive dependencies.