CVE-2025-13736: wso2 api_manager Observable Discrepancy
Vulnerability summary
CVE-2025-13736 is a low (CVSS 3.7) Observable Discrepancy vulnerability in wso2 api_manager. EPSS estimates a 0.27% chance of exploitation in the next 30 days, higher than 17.9% of scored vulnerabilities.
Timeline
- 06-08-2026PublishedVulnerability first disclosed.
- 06-08-2026Last modifiedVulnerability information updated.
Description
When Multi-Attribute Login is enabled, the login interface fails to consistently mask the existence of user accounts. For valid users, the server resolves and displays their canonical username, while for non-existent users, it echoes the original input. This occurs regardless of the validate_username configuration. The discovery of valid usernames can increase the risk of brute force attacks, social engineering attacks, and targeted information leakage. Attackers can leverage this information to craft more effective phishing campaigns or social engineering tactics to compromise user accounts or extract sensitive data.
CVSS metrics
2 scores · 2 sources · 1 version- NVDNIST3.7LowCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
EPSS trend
Probability
0.27%
Chance of exploitation in the next 30 days
Percentile
18%
Versus all other CVEs
30-day change
+0.10 pp
From 0.17% on 20-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Wso210 products
- api_manager≥ 3.1.0, < 3.1.0.351 | ≥ 3.2.0, < 3.2.0.455 | ≥ 4.0.0, < 4.0.0.375
- identity_server≥ 5.10.0, < 5.10.0.380 | ≥ 5.11.0, < 5.11.0.427 | ≥ 6.0.0, < 6.0.0.254 | ≥ 6.1.0, < 6.1.0.255 | ≥ 7.0.0, < 7.0.0.132 | ≥ 7.1.0, < 7.1.0.40 | ≥ 7.2.0, < 7.2.0.2
- identity_server_as_key_manager≥ 5.10.0, < 5.10.0.371
- open_banking_am≥ 2.0.0, < 2.0.0.400
- open_banking_iam≥ 2.0.0, < 2.0.0.420
1 vendor · 10 products