VulnerabilityPublished 11 May 2026

CVE-2024-0391: WSO2 Identity Server · Observable Response Discrepancy

Affects WSO2 Identity ServerSource CVE Database V5

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Not known to be exploited · CVSS 5.3 Medium · fixed in 7.0.0.131 : update WSO2 Identity Server when convenient.

Data as of 30 Oct 2026, 11:52 UTC

CVSS 3.1 base score

5.3Medium

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

EPSS: 0.1% chance of exploitation in 30 days – higher than 7% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 7.0.0.131, 6.1.0.254, 6.0.0.253 +11

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

Attack Vector: Network
Attack Complexity: Low
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: 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: 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 11 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 30 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.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), 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

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
WSO2WSO2 Identity Server	Affected >=7.0.0 <7.0.0.131	Fixed in 7.0.0.131
WSO2WSO2 Identity Server	Affected >=6.1.0 <6.1.0.254	Fixed in 6.1.0.254
WSO2WSO2 Identity Server	Affected >=6.0.0 <6.0.0.253	Fixed in 6.0.0.253
WSO2WSO2 Identity Server	Affected >=5.11.0 <5.11.0.431	Fixed in 5.11.0.431
WSO2WSO2 Identity Server	Affected >=5.11.0 <5.11.0.426	Fixed in 5.11.0.426
WSO2WSO2 Identity Server	Affected >=5.10.0 <5.10.0.379	Fixed in 5.10.0.379

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

If you cannot patch yet, consider restricting access to the affected functionality or implementing additional rate limiting and monitoring to detect enumeration attempts.

Description

CVE-2024-0391 is a medium severity vulnerability in WSO2 Identity Server versions 5.10.0 through 7.0.0. It involves an observable response discrepancy in the email OTP flow's user account lock state check, which fails to properly validate user input. This flaw allows an attacker to determine whether specific usernames are registered in the system. Such information disclosure can facilitate brute-force and social engineering attacks, increasing risks to user data and organizational security.

Impact

An attacker can leverage this vulnerability to enumerate valid usernames by observing response discrepancies during the email OTP flow. This information disclosure increases the risk of targeted brute-force attacks and social engineering campaigns such as phishing. While the vulnerability does not directly allow data modification or denial of service, the indirect impact includes potential compromise of user accounts and reputational damage to the organization.

Summary

The vulnerability CVE-2024-0391 in WSO2 Identity Server arises from improper validation in the email OTP flow's check for user account lock states. This leads to observable differences in responses that enable attackers to confirm the existence of user accounts. The affected versions include 5.10.0, 5.11.0, 6.0.0, 6.1.0, and 7.0.0. The CVSS 3.1 base score is 5.3 (medium severity), reflecting network attack vector, low complexity, no privileges or user interaction required, and limited confidentiality impact.

CWE-204Observable Response Discrepancy (opens in a new tab)
Base weakness
The product provides different responses to incoming requests in a way that reveals internal state information to an unauthorized actor outside of the intended control sphere.
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
ICMP IP Total Length Field Probe (opens in a new tab)
ICMP IP 'ID' Field Error Message Probe (opens in a new tab)
Application Fingerprinting (opens in a new tab)
System Footprinting (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/2026/WSO2-2024-3115/ (opens in a new tab)

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 18 May 2026, 10:48 UTC

WeaknessesCWE-204

Technical details

References

Community reviews

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