VulnerabilityPublished 15 Sep 2026

CVE-2025-5802: WSO2 API Manager · Information Disclosure Through Error Messages

Affects WSO2 API ManagerSource CVE Database V5

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Not known to be exploited · CVSS 5.3 Medium · fixed in 4.6.0.17 : update WSO2 API Manager 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: 0.3% chance of exploitation in 30 days – higher than 26% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 4.6.0.17, 4.5.0.55, 4.4.0.72 +27

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 15 Sep 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 API Manager	Affected >=4.6.0 <4.6.0.17	Fixed in 4.6.0.17
WSO2WSO2 API Manager	Affected >=4.5.0 <4.5.0.55	Fixed in 4.5.0.55
WSO2WSO2 API Manager	Affected >=4.4.0 <4.4.0.72	Fixed in 4.4.0.72
WSO2WSO2 API Manager	Affected >=4.3.0 <4.3.0.112	Fixed in 4.3.0.112
WSO2WSO2 API Manager	Affected >=4.2.0 <4.2.0.200	Fixed in 4.2.0.200
WSO2WSO2 API Manager	Affected >=4.1.0 <4.1.0.262	Fixed in 4.1.0.262

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 modifying error messages to avoid revealing username existence or implementing rate limiting on registration attempts to reduce enumeration risk.

Description

The self-registration flow accepts user-supplied input for usernames without adequately preventing the disclosure of username existence. When a user attempts to register with an existing username, the system responds with an error message that explicitly indicates the username is already in use. This behavior allows an attacker to discover valid usernames within the system. The discovery of valid usernames can facilitate subsequent attacks such as brute force, social engineering, and targeted phishing campaigns.

Impact

An attacker can enumerate valid usernames by observing error messages during the self-registration process. This information disclosure can facilitate targeted attacks such as brute force login attempts, social engineering, and phishing campaigns. There is no direct impact on integrity or availability reported.

Summary

The vulnerability arises because the self-registration process in WSO2 API Manager does not adequately prevent information disclosure through error messages. When a user tries to register with a username that already exists, the system responds with an error message explicitly stating the username is taken. This behavior enables attackers to confirm valid usernames in the system. The issue is identified as CWE-203 (Information Exposure Through Discrepancy). Multiple versions across 2.x, 3.x, 4.x, 5.x, 6.x, and 7.x branches are affected, with specific upper bounds indicating patched versions. No known exploits are reported in the wild. The CVSS 3.1 vector is AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N, reflecting network attack vector, low attack complexity, no privileges or user interaction required, unchanged scope, and limited confidentiality impact.

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/2026/WSO2-2025-4227/ (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 15 Sep 2026, 10:18 UTC

WeaknessesCWE-203

Technical details

References

Community reviews

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