Cybozu Garoon: Improper Handling of Extra Values
CVE-2026-22888 is a high-severity improper handling of extra values vulnerability in Cybozu Garoon from Cybozu, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Cybozu Garoon versions: 5.0.0 to 6.0.3. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.45% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Garoon to 6.0.3 or a later version.
- Read the advisory on kb.cybozu.support for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Cybozu | Cybozu Garoon | 5.0.0 to 6.0.3 | Not stated |
| Cybozu | Garoon | 5.0.0 up to, but not including, 6.0.3 | 6.0.3 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 6.9 | Medium | CNA (jpcert.or.jp) |
| CVSS 3.1 | 7.5 | High | NVD |
| CVSS 3.0 | 4.9 | Medium | CNA (jpcert.or.jp) |
Official description
Improper input verification issue exists in Cybozu Garoon 5.0.0 to 6.0.3, which may lead to unauthorized alteration of portal settings, potentially blocking access to the product.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Handling of Extra Values
The product does not handle or incorrectly handles when more values are provided than expected.
More Improper Handling of Extra Values vulnerabilities (CWE-231)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Third-party and government advisories
- jvn.jp/en/jp/JVN35265756/Third Party Advisory
Other vulnerabilities in Cybozu Garoon
- 9.0 Critical severity
Recent Improper Handling of Extra Values vulnerabilities
- 7.7 High severity
- 7.5 High severity
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