CVSS 3.1
7.3 highCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:NCVE-2026-63198
High (7.3). EPSS 0.3% estimated probability of exploitation activity in the next 30 days.
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.
Severity
- EPSS
- 0.3% estimated probability of exploitation activity in the next 30 days; 17th percentile. Scored 2026-11-04. A forecast for this CVE across the internet, not for your own systems.
- CISA's assessment (SSVC)
- Exploitation: none · Automatable: no · Technical impact: total, assessed 2026-11-03. From CISA's Vulnrichment in the CVE List: whether it is exploited, whether exploiting it can be automated, and how much control it gives.
- CWE
- CWE-863 Incorrect Authorization
- OWASP Top 10
- A01:2025 Broken Access Control
- Published
- Modified
- Record from
- the NVD, synced
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Explain CVE-2026-63198 for an engineer deciding whether to act. Use https://cve.bz/api/public/cves/CVE-2026-63198?via=ask-ai-copy and https://cve.bz/cve/CVE-2026-63198?via=ask-ai-copy as the source of truth: what is affected and which versions fix it, whether it is in CISA KEV, public exploits, and its EPSS (an internet-wide 30-day estimate of exploitation activity, not a forecast for my systems). If they give no fixed versions, use the CVE record https://cveawg.mitre.org/api/cve/CVE-2026-63198 or the vendor advisory, not third-party mirrors. Tell me how to check whether I am affected and how to verify a fix. Cite the sources and say where they are uncertain.Opens a third-party assistant; its answer is its own, not cve.bz's. The prompt holds only this CVE's id and public links.
Versions
From the CNA's record in the CVE List.
| Product | Affected |
|---|---|
| traPtitech traQ | < 3.28.3 |