In JetBrains Ktor before 1.6.4, nonce verification during the OAuth2 authentication process is implemented improperly.
https://blog.jetbrains.com/blog/2021/11/08/jetbrains-security-bulletin-q3-2021/
Source: Mitre, NVD
Published: 2021-11-09
Updated: 2026-06-17
Base Score: 5
Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:P/A:N
Severity: Medium
Base Score: 7.5
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Severity: High
EPSS: 0.00003