CVE-2023-42793
CriticalExploitedPublic exploitIn JetBrains TeamCity before 2023.05.4 authentication bypass leading to RCE on TeamCity Server was possible
Published Sep 26, 2023 · Updated Oct 21, 2025 · Also known as TR-23-0556
Key Facts
Patch immediately- CVE-2023-42793 is a critical-severity vulnerability (CVSS 9.8 v3.1) affecting TeamCity (Jetbrains).
- It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Oct 1, 2023 and is known to be used in ransomware campaigns. Public exploit code is available.
- EPSS estimates a 100% probability of exploitation in the next 30 days.
- Fixed versions are available, including TeamCity 2023.05.4.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
9.8
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS (30-day exploit likelihood)
100%
Higher than 99.9% of all scored CVEs
Exploited in the wild
Yes
4 catalog listings, used by ransomware
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2023-42793 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
Description
In JetBrains TeamCity before 2023.05.4 authentication bypass leading to RCE on TeamCity Server was possible
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| CISA KEV | Oct 4, 2023 | Oct 25, 2023 | Known |
| Industry KEV feed | Oct 1, 2023 | Oct 25, 2023 | Known |
| CIRCL KEV | Oct 4, 2023 | Oct 25, 2023 | Known |
| ENISA EUVD | Oct 4, 2023 | n/a | Not reported |
Required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Affected Products
2 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| TeamCityJetbrains | See advisory | 2023.05.4 |
Patched Releases
TeamCity
2023.05.4
Timeline
Publicly disclosed
Sep 26, 2023
Added to Industry KEV feed
Oct 1, 2023
Added to CISA KEV
Oct 4, 2023
Added to CIRCL KEV
Oct 4, 2023
Added to ENISA EUVD
Oct 4, 2023
Last updated
Oct 21, 2025
Weakness Type
- CWE-288 Authentication Bypass Using an Alternate Path or Channel
- CWE-306 Missing Authentication for Critical Function
References
- advisoryhttps://attackerkb.com/topics/1XEEEkGHzt/cve-2023-42793
- advisoryhttps://blog.jetbrains.com/teamcity/2023/09/critical-security-issue-affecting-teamcity-on-premises-update-to-2023-05-4-now/
- advisoryhttps://blog.jetbrains.com/teamcity/2023/09/cve-2023-42793-vulnerability-post-mortem/
- advisoryhttps://gixtools.net/2023/09/critical-jetbrains-teamcity-flaw-could-expose-source-code-and-build-pipelines-to-attackers/
- advisoryhttps://thehackernews.com/2023/09/critical-jetbrains-teamcity-flaw-could.html
FAQ
Common Questions.
In JetBrains TeamCity before 2023.05.4 authentication bypass leading to RCE on TeamCity Server was possible
Affected: TeamCity (Jetbrains). The full list is in the CVE brief.
It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Oct 1, 2023 and is known to be used in ransomware campaigns.
Yes. It was added on Oct 4, 2023 with a federal remediation due date of Oct 25, 2023.
Public exploit code is available.
Fixed versions are available, including TeamCity 2023.05.4.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
Is CVE-2023-42793 Running On Your Attack Surface?
Brandefense maps vulnerabilities like this one to your internet-facing assets and tells you exactly where to patch.
Request A Demo