traQ: Privilege escalation by OAuth prompt=none request
cve-program · CVE-2026-63198
PublishedtraQ 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.
Read the publisher's advisoryeuvd · EUVD-2026-116132
PublishedtraQ 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.
Read the publisher's advisorynvd · CVE-2026-63198
PublishedtraQ 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.
Read the publisher's advisoryosv · GHSA-8cfq-jgf7-8m27
PublishedIn OAuth2 silent authorization (`prompt=none`), when the `scope` parameter was empty or omitted, all scopes registered for the OAuth client became eligible for issuance. However, the prior consent check was performed against the empty requested scope set. As a result, an attacker could obtain an access token with broader scopes than the user had previously consented to, without requiring additional consent. ## Impact If an attacker controls an OAuth client capable of receiving authorization codes, and a user has already consented to only a subset of that client’s scopes, the attacker may be able to obtain a token containing all scopes registered for that client by sending an authorization request with `prompt=none` and an empty or omitted `scope`. If the user has not consented to the client at all, `consent_required` is returned as usual. ## Patches This issue has been fixed in v3.28.3. After the fix, the consent check for `prompt=none` verifies the scopes that will actually be issued, rather than the empty requested scope set. If the user has not consented to all scopes after expansion, `consent_required` is returned. traQ also recommends revoking any existing OAuth tokens created before the fix if they were potentially affected. ## Workarounds If users cannot update immediately, they should apply the following mitigations: - Disable untrusted OAuth clients, minimize registered client scopes, and revoke existing tokens - Reject authorization requests with `prompt=none` where `scope` is empty or omitted
Read the publisher's advisoryAffected versions, risk and source history
Exploitation and risk
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cve-program · CVE-2026-63198
PublishedtraQ: Privilege escalation by OAuth prompt=none request
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.
- Source published
- 3 Nov 2026 18:38:35 UTC
- Source modified
- 3 Nov 2026 19:37:45 UTC
- Saved here
- 3 Nov 2026 21:57:16 UTC
- Source terms
- CVE Program Terms of Use
Original source record · Cite this exact observation · Complete original publisher JSON
Source: cve-program · CVE Program Terms of Use. The publisher's wording is preserved. ChangeIntel groups the information and labels changes. The JSON record includes additional source fields.
CVSS 3.1 · 7.3 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N
euvd · EUVD-2026-116132
PublishedtraQ 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…
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.
Additional publisher context
EUVD source date text has no stated timezone and is retained without inventing a UTC instant. Related bulletin membership is not an alias, common cause or applicability claim. A missing vector with a zero score is treated as unrated. Complete vendor/product and underlying source evidence remains in the original JSON.
Original publisher date fields
datePublished: Nov 3, 2026, 6:38:35 PM
dateUpdated: Nov 3, 2026, 7:37:45 PM
- Source published
- Nov 3, 2026, 6:38:35 PM (timezone not stated)
- Source modified
- Nov 3, 2026, 7:37:45 PM (timezone not stated)
- Saved here
- 13 Nov 2026 22:08:35 UTC
- Source terms
- ENISA EUVD · source terms and attribution apply
Original source record · Cite this exact observation · Complete original publisher JSON
Source: euvd · ENISA EUVD · source terms and attribution apply. The publisher's wording is preserved. ChangeIntel groups the information and labels changes. The JSON record includes additional source fields.
EUVD CVSS 3.1 · 7.3 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N
nvd · CVE-2026-63198
PublishedtraQ 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…
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.
Additional publisher context
NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON.
Source analysis status: Deferred
Weakness classifications: CWE-863
Original publisher date fields
published: 2026-11-03T19:18:09.080
lastModified: 2026-11-12T22:18:51.470
- Source published
- 3 Nov 2026 19:18:09 UTC
- Source modified
- 12 Nov 2026 22:18:51 UTC
- Saved here
- 13 Nov 2026 22:01:12 UTC
- Source terms
- NIST NVD usage terms; underlying source attribution retained
Original source record · Cite this exact observation · Complete original publisher JSON
Source: nvd · NIST NVD usage terms; underlying source attribution retained. The publisher's wording is preserved. ChangeIntel groups the information and labels changes. The JSON record includes additional source fields.
CVSS 3.1 · [email protected] · Secondary · 7.3 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N
osv · GHSA-8cfq-jgf7-8m27
PublishedtraQ: Privilege escalation by OAuth prompt=none request
In OAuth2 silent authorization (`prompt=none`), when the `scope` parameter was empty or omitted, all scopes registered for the OAuth client became eligible for issuance. However, the prior consent check was performed against the empty requested scope set. As a result, an attacker could obtain an access token with broader scopes than the user had previously consented to, without requiring additional consent. ## Impact If an attacker controls an OAuth client capable of receiving authorization codes, and a user has already consented to only a subset of that client’s scopes, the attacker may be able to obtain a token containing all scopes registered for that client by sending an authorization request with `prompt=none` and an empty or omitted `scope`. If the user has not consented to the client at all, `consent_required` is returned as usual. ## Patches This issue has been fixed in v3.28.3. After the fix, the consent check for `prompt=none` verifies the scopes that will actually be issued, rather than the empty requested scope set. If the user has not consented to all scopes after expansion, `consent_required` is returned. traQ also recommends revoking any existing OAuth tokens created before the fix if they were potentially affected. ## Workarounds If users cannot update immediately, they should apply the following mitigations: - Disable untrusted OAuth clients, minimize registered client scopes, and revoke existing tokens - Reject authorization requests with `prompt=none` where `scope` is empty or omitted
- Source published
- 9 Nov 2026 20:55:17 UTC
- Source modified
- 9 Nov 2026 21:00:04 UTC
- Saved here
- 9 Nov 2026 21:04:16 UTC
- Source terms
- GitHub Advisory Database · CC-BY-4.0
Original source record · Cite this exact observation · Complete original publisher JSON
Source: osv · GitHub Advisory Database · CC-BY-4.0. The publisher's wording is preserved. ChangeIntel groups the information and labels changes. The JSON record includes additional source fields.
CVSS_V3 · CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N
Publisher rating · HIGH