traQ: Privilege escalation by OAuth prompt=none request

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

7.3 · CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N

EPSS

• CVE-2026-63198: 0.26% estimated exploitation activity in the next 30 days; percentile 17.27 (FIRST EPSS, 2026-11-10). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

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…

Published by the source

9 Nov 2026, 20:55 UTC

Last modified by the source

9 Nov 2026, 21:00 UTC

Source last checked

10 Nov 2026, 06:45 UTC

1. Revision 2 · amended · 10 Nov 2026

   Amended from osv record GHSA-8cfq-jgf7-8m27

2. Revision 1 · created · 9 Nov 2026

   Published from ghsa record GHSA-8cfq-jgf7-8m27

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# Patch Next advisory brief: CVE-2026-63198

Advisory: traQ: Privilege escalation by OAuth prompt=none request
IDs: CVE-2026-63198, GHSA-8cfq-jgf7-8m27
Record: https://patchnext.com/advisories/cve-2026-63198 (revision 2, source checked 10 Nov 2026, 06:45 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/traPtitech/traQ 1.0.0-rc.2.0.20260629134940-5510fe8aa9bb. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/traPtitech/traQ: affected < 1.0.0-rc.2.0.20260629134940-5510fe8aa9bb; fixed in 1.0.0-rc.2.0.20260629134940-5510fe8aa9bb

## Suggested inspection (read-only)
- Go github.com/traPtitech/traQ: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/traPtitech/traQ.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-8cfq-jgf7-8m27 (GitHub-reviewed advisory GHSA-8cfq-jgf7-8m27 lists affected ranges: Go github.com/traPtitech/traQ >=0 <1.0.0-rc.2.0.20260629134940-5510fe8aa9bb)
- Verified: https://osv.dev/vulnerability/GHSA-8cfq-jgf7-8m27 (OSV record GHSA-8cfq-jgf7-8m27 lists affected ranges: Go github.com/traPtitech/traQ >=0 <1.0.0-rc.2.0.20260629134940-5510fe8aa9bb (fixed))

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