by Kastro
Paper/Archive/CVE-2026-39999

CVE-2026-39999

Apache Software Foundation Apache APISIX — Apache APISIX: JWT Algorithm Confusion allows authentication bypass

EPSS 0.6%CVSS 9.1
critical.is priorityof 100
37
CVSS 9.1 (NVD)9.1 / 10 × 3027.3Not in CISA KEV+300.0EPSS percentile 50.4.504 × 2010.1No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

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 the issue.

Affected

ProductAffectedFixed inSource
Apache APISIX2.2 – 3.16.0–CNA

Scores by source

NVD9.1CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
apache (CNA)7.0CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N
CISA ADPSSVCExploitation: none · Automatable: yes · Technical impact: partial

References

advisorylists.apache.org/thread/nfopt8cnxd3k0rs1oxtr7lzxrdw4mojqrefopenwall.com/lists/oss-security/2026/06/19/5