VulnerabilityPublished 12 Dec 2025

CVE-2025-58576: Japan Total System GroupSession Free edition · Cross-site Request Forgery (CSRF)

Affects Japan Total System GroupSession Free editionSource CVE Database V5

Not known to be exploited · CVSS 4.3 Medium : upgrade to 5.3.0 when convenient.

Data as of 26 Oct 2026, 09:08 UTC

CVSS 3.0 base score

4.3Medium

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

EPSS: 0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 5.3.0

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

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

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: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: Required: Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited.
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: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 12 Dec 2025
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 26 Oct 2026.

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

Upgrade Japan Total System GroupSession Free edition to 5.3.0.

Affected software

Product	Affected	Fixed in
Japan Total System Co.,Ltd. GroupSession Free edition	Affected <5.3.0	Fixed in 5.3.0

AI-suggested

1. 2. In the interim, implement web application firewall (WAF) rules to detect and block suspicious cross-site requests targeting GroupSession endpoints. 3. Enable and enforce anti-CSRF tokens in all forms and state-changing requests within the application if configurable. 4. Restrict the use of HTTP methods that can cause state changes (e.g., POST, PUT) to trusted origins only via CORS policies. 5. Educate users about the risks of clicking unknown or suspicious links while logged into GroupSession, emphasizing phishing awareness. 6. Monitor user activity logs for unusual or unauthorized operations that could indicate exploitation attempts. 7. Consider isolating GroupSession access to trusted networks or VPNs to reduce exposure. 8. Regularly review and update session management policies to minimize session lifetime and reduce risk from stolen sessions.

Description

Cross-site request forgery vulnerability exists in GroupSession Free edition prior to ver5.3.0, GroupSession byCloud prior to ver5.3.3, and GroupSession ZION prior to ver5.3.2. If a user accesses a malicious page while logged in, unintended operations may be performed.

Impact

For European organizations using GroupSession products, this vulnerability poses a risk of unauthorized actions being performed within their collaboration environment if users are tricked into visiting malicious websites. While it does not compromise data confidentiality or system availability, the integrity of data and operations can be affected, potentially leading to workflow disruptions, unauthorized changes to shared documents or settings, and loss of trust in the collaboration platform. Organizations with remote or hybrid workforces are particularly vulnerable due to increased exposure to phishing and social engineering attacks. The medium severity rating reflects the limited scope of impact but acknowledges the ease of exploitation via user interaction. If exploited at scale, it could lead to operational inefficiencies and require incident response efforts. The absence of known exploits in the wild reduces immediate risk but does not eliminate the threat, especially as attackers often develop exploits following public disclosure. European entities relying on GroupSession for critical collaboration should consider this vulnerability a priority for remediation to maintain operational integrity.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 19 Dec 2025, 08:30 UTC

Technical details

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