CVE-2026-39999
Published: 19 June 2026
Summary
CVE-2026-39999 is a high-severity Authentication Bypass by Spoofing (CWE-290) vulnerability in Apache Apisix. Its CVSS base score is 7.0 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Forge Web Credentials (T1606); ranked at the 30.6th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-38013
Vulnerability details
Authentication Bypass by Spoofing vulnerability in Apache APISIX. The attacker can completely bypass authentication capitalising on certain configurations of jwt-auth plugin. This issue affects Apache APISIX: from v2.2 through v3.16.0. Users are recommended to upgrade to version v3.17.0, which fixes…
more
the issue.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
JWT auth bypass via spoofing directly enables forging of web credentials/tokens.
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Reveals spoofed logon attempts through unexpected previous logon timestamps upon legitimate login.
Training specifically addresses recognizing spoofed communications and phishing that enable authentication bypass.
Requiring verifiable identity evidence at appropriate assurance levels makes it substantially harder for attackers to successfully spoof or impersonate users to obtain accounts.
Unique device authentication makes successful spoofing of device identity substantially more difficult to achieve.
Unique identification of non-organizational users reduces the feasibility of authentication bypass by spoofing.
Unique identification and authentication of services before communications makes spoofing of service identities substantially harder.
Isolated trusted path ensures the user interacts only with genuine system components, preventing spoofing of authentication interfaces or prompts.
Directly counters DNS response spoofing by requiring cryptographic origin authentication artifacts from the authoritative source.