Missing authentication
A sensitive function is reachable without proving who is using it.
CWE-306 · NVD record: nvd@nist.gov
Reading and practice labs · Free account for labs. Basic HTTP knowledge; some labs use Burp Suite.
Exploited. On CISA's list since 2023-10-04, and used by ransomware.
JetBrains TeamCity Authentication Bypass Vulnerability
CVE-2023-42793 · JetBrains TeamCity · Published 2023-09-19
How bad would it be?
9.8 out of 10
CVSS rates it critical: about as damaging as flaws get.
How likely is it to be used?
over 99%
Estimated chance of exploitation in the next 30 days, among the top 1% of all scored flaws (EPSS, 2026-10-29).
Is it already being used?
Yes
CISA has seen it exploited in real attacks. For US government agencies the fix is deadline passed 1101 days ago (2023-10-25).
What CISA says to do
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
JetBrains TeamCity contains an authentication bypass vulnerability that allows for remote code execution on TeamCity Server.
What the flaw is
In JetBrains TeamCity before 2023.05.4 authentication bypass leading to RCE on TeamCity Server was possible
From the NVD.
Fixes and advisories
Learn this
Explore this week’s weaknesses and all learning topics
Understand the kind of weakness behind this flaw. These resources teach the weakness, rather than reproduce this specific CVE. Follow the vendor's advice above to fix the affected product.
CWE-288 · CISA KEV; NVD record: cve@jetbrains.com. We have not selected a close learning match for this label.
CWE is a catalogue of weakness types. Labels come from the sources shown and can differ or change. Resource matches reviewed 16 October 2026.
On SentryFeed
No story in the last 14 days has mentioned it.
Exploited flaws from CISA's KEV catalogue. Chance of exploitation from EPSS by FIRST. Descriptions and scores from the NVD. This product uses the NVD API but is not endorsed or certified by the NVD.