CVE-2026-22888VulnerabilityPublished 2 Feb 2026

CVE-2026-22888: Cybozu Garoon · Improper handling of extra values

Affects Cybozu GaroonSource CVE Database V5

Not known to be exploited · CVSS 4.9 Medium.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 3.0 base score

4.9Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.4% chance of exploitation in 30 days – higher than 39% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H

Attack Vector: Network
Attack Complexity: Low
Privileges Required: High
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: High: The attacker is authorized with (i.e., requires) privileges that provide significant (e.g., administrative) control over the vulnerable component that could affect component-wide settings and files.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 2 Feb 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
Cybozu, Inc.Cybozu Garoon	Affected =5.0.0 to 6.0.3	Fixed in–

AI-suggested

1. Apply official patches from Cybozu as soon as they become available to address the input validation flaw. 2. Restrict administrative access to Cybozu Garoon to trusted personnel only, using strong authentication methods such as multi-factor authentication. 3. Implement network segmentation to limit access to the management interfaces of Cybozu Garoon. 4. Monitor portal configuration changes and audit logs for unauthorized or unusual modifications to detect potential exploitation attempts early. 5. Conduct regular security training for administrators to recognize and prevent misuse of privileged access. 6. If patching is delayed, consider temporary compensating controls such as disabling non-essential administrative functions or restricting access to the portal settings interface. 7. Maintain up-to-date backups of configuration and data to enable rapid recovery in case of disruption. 8. Engage with Cybozu support and security advisories to stay informed about updates and mitigation guidance.

Description

CVE-2026-22888 is a medium severity vulnerability in Cybozu Garoon versions 5.0.0 through 6.0.3 caused by improper input verification. This flaw allows an authenticated user with high privileges to manipulate portal settings without proper validation, potentially resulting in denial of access to the product. The vulnerability does not impact confidentiality or integrity directly but can cause availability disruption. Exploitation requires network access and high privileges but no user interaction. No known exploits are currently reported in the wild. European organizations using affected versions of Cybozu Garoon should prioritize patching or mitigating this issue to avoid operational disruption.

Impact

For European organizations, the primary impact is on availability and operational continuity. Cybozu Garoon is used in various industries for internal communication and portal management; disruption could hinder business workflows and collaboration. Organizations relying heavily on this platform may face downtime or restricted access, affecting productivity. Since exploitation requires high privileges, insider threats or compromised administrative accounts pose a significant risk. The lack of confidentiality or integrity impact limits data breach concerns but does not reduce the operational risk. Sectors with critical dependency on Cybozu Garoon, such as government agencies, financial institutions, and large enterprises, could experience significant disruption. The absence of known exploits reduces immediate threat but does not eliminate future risk, especially if attackers develop exploit code. European entities should consider the vulnerability in their risk assessments and incident response planning.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 9 Feb 2026, 10:59 UTC

Technical details

References

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