VulnerabilityPublished 26 Sep 2025Updated 30 Sep 2025

CVE-2025-1396: WSO2 Identity Server · Observable Discrepancy

Affects WSO2 Identity ServerSource CVE Database V5

Not known to be exploited · CVSS 3.7 Low.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 3.1 base score

3.7Low

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

EPSS: 0.2% chance of exploitation in 30 days – higher than 16% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Attack Vector: Network
Attack Complexity: High
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: Low
Integrity: None
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: High: A successful attack depends on conditions beyond the attacker's control. That is, a successful attack cannot be accomplished at will, but requires the attacker to invest in some measurable amount of effort in preparation or execution against the vulnerable component before a successful attack can be expected. For example, a successful attack may require an attacker to: gather knowledge about the environment in which the vulnerable target/component exists; prepare the target environment to improve exploit reliability; or inject themselves into the logical network path between the target and the resource requested by the victim in order to read and/or modify network communications (e.g., a man in the middle attack).
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: 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: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: None: There is no loss of integrity within 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 26 Sep 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 or the CVSS exploit maturity 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
WSO2 WSO2 Identity Server	Affected 5.10.0 – 6.1.0 4 affected builds	Fixed in–

AI-suggested

To mitigate this vulnerability, European organizations should first verify if Multi-Attribute Login is enabled on their WSO2 Identity Server deployments and assess if affected versions (5.10.0, 5.11.0, 6.0.0, 6.1.0) are in use. If so, organizations should consider disabling Multi-Attribute Login temporarily until a patch or update is available that addresses the issue. Alternatively, configuring the system to return generic error messages that do not reveal whether a username exists can prevent information leakage. Implementing account lockout or throttling mechanisms after multiple failed login attempts can reduce the risk of brute-force attacks. Monitoring authentication logs for unusual login attempts or enumeration patterns is also recommended. Organizations should enforce strong password policies and encourage multi-factor authentication (MFA) to reduce the impact of username enumeration. Finally, staying updated with WSO2 security advisories and applying patches promptly once released is critical. Network-level protections such as Web Application Firewalls (WAFs) can be tuned to detect and block enumeration attempts based on request patterns.

Description

A username enumeration vulnerability exists in multiple WSO2 products when Multi-Attribute Login is enabled. In this configuration, the system returns a distinct "User does not exist" error message to the login form, regardless of the validate_username setting. This behavior allows malicious actors to determine which usernames exist in the system based on observable discrepancies in the application's responses. Exploitation of this vulnerability could aid in brute-force attacks, targeted phishing campaigns, or other social engineering techniques by confirming the validity of user identifiers within the system.

Impact

For European organizations using WSO2 Identity Server with Multi-Attribute Login enabled, this vulnerability poses a risk primarily to user confidentiality. Attackers can enumerate valid usernames, which can significantly aid in crafting more effective brute-force attacks or social engineering campaigns such as spear phishing. This can lead to unauthorized access if combined with weak password policies or reused credentials. While the vulnerability does not directly compromise system integrity or availability, the information leakage can be a stepping stone for more severe attacks. Organizations in sectors with high regulatory requirements for data protection, such as finance, healthcare, and government, may face increased risk of targeted attacks exploiting this vulnerability. Additionally, the exposure of valid usernames could violate privacy regulations like GDPR if it leads to unauthorized access or data breaches. The low CVSS score indicates limited direct impact, but the indirect consequences through chained attacks could be significant, especially in environments with sensitive data or critical infrastructure.

CWE-203Observable Discrepancy (opens in a new tab)
Base weakness
The product behaves differently or sends different responses under different circumstances in a way that is observable to an unauthorized actor.
Architecture and Design · Separation of Privilege
Compartmentalize the system to have "safe" areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area.
Implementation
Ensure that error messages only contain minimal details that are useful to the intended audience and no one else. The messages need to strike the balance between being too cryptic (which can confuse users) or being too detailed (which may reveal more than intended).
OWASP Cheat Sheets
Error Handling (opens in a new tab)
Logging (opens in a new tab)
OWASP ASVS 4.0.3
V8.3.4 (opens in a new tab)
V14.3.3 (opens in a new tab)
V7.3.3 (opens in a new tab)
Attack patterns
Black Box Reverse Engineering (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

security.docs.wso2.com/en/latest/security-announcements/security-advisories/2025/WSO2-2025-3983/ (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 4 Oct 2025, 00:28 UTC

WeaknessesCWE-203

Technical details

References

Community reviews

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