---
id: "CVE-2023-42793"
kind: "vulnerability"
aliases: ["CVE-2023-42793"]
title: "In JetBrains TeamCity before 2023.05.4 authentication bypass leading to RCE on TeamCity Server was possible"
severity: "critical"
cvss: 9.8
epss: null
exploited: true
status: "open"
category: "runtime"
products: [{"name": "jetbrains teamcity", "fixed": ["2023.05.4"], "affected": "< 2023.05.4", "ecosystem": "vendor"}, {"name": "JetBrains TeamCity", "fixed": [], "affected": "", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["ci-cd", "exploited", "jetbrains", "ransomware", "runtime", "self-hosted", "teamcity"]
not_affected_if: ["managed-hosting"]
published_at: "2023-09-19T17:15:08+00:00"
first_seen_at: "2026-10-23T19:11:51+00:00"
updated_at: "2026-10-24T00:09:51+00:00"
sources: [{"source": "kev", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2023-42793", "first_seen_at": "2026-10-23T19:11:51+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2023-42793", "first_seen_at": "2026-10-23T22:29:04+00:00"}]
---

# In JetBrains TeamCity before 2023.05.4 authentication bypass leading to RCE on TeamCity Server was possible

JetBrains TeamCity Server has an authentication bypass that lets an unauthenticated remote attacker run code on the server. CISA lists it as actively exploited in the wild, with ransomware use noted in the sources.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:jetbrains teamcity affected < 2023.05.4 fixed 2023.05.4
- vendor:JetBrains TeamCity affected ? fixed ?

## Fix

Apply the JetBrains mitigation or upgrade to the fixed TeamCity version per vendor instructions; discontinue use if no mitigation is available (per CISA required action). Affected and fixed version ranges are not stated in the sources.

## Timeline

- 2026-10-23T19:11:51+00:00 kev https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2023-42793
- 2026-10-23T22:29:04+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2023-42793

## From the sources

JetBrains TeamCity contains an authentication bypass vulnerability that allows for remote code execution on TeamCity Server.

CISA required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_