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Known Exploited Vulnerability
9.8
CRITICAL CVSS 3.1
CVE-2026-63077
JetBrains TeamCity Deserialization of Untrusted Data Vulnerability - [Actively Exploited]
Overview
Description

In JetBrains TeamCity before 2026.1.3, 2025.11.7 unauthenticated remote code execution was possible via the agent polling protocol

Details
INFO

Published Date :

July 27, 2026, 5:16 p.m.

Last Modified :

Aug. 6, 2026, 5:17 a.m.

Remotely Exploit :

Yes !

Source :

[email protected]
CISA Notification
CISA KEV (Known Exploited Vulnerabilities)

For the benefit of the cybersecurity community and network defenders—and to help every organization better manage vulnerabilities and keep pace with threat activity—CISA maintains the authoritative source of vulnerabilities that have been exploited in the wild.

Description :

JetBrains TeamCity contains a deserialization of untrusted data vulnerability that could allow unauthenticated remote code execution via the agent polling protocol.

Required Action :

Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

Known Ransomware Campaign Use:

Unknown

Notes :

https://blog.jetbrains.com/teamcity/2026/07/cve-2026-63077/; https://www.jetbrains.com/privacy-security/issues-fixed/ ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2026-63077

Impact
Affected Products

The following products are affected by CVE-2026-63077 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Jetbrains teamcity
: Total Affected Vendor : 1 | Products : 1
Scoring
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 134c704f-9b21-4f2e-91b3-4a467353bcc0
CVSS 3.1 CRITICAL 547ada31-17d8-4964-bc5f-1b8238ba8014
CVSS 3.1 CRITICAL [email protected]
Solution
Update JetBrains TeamCity to a patched version to fix unauthenticated remote code execution.
  • Update JetBrains TeamCity to a fixed version.
  • Apply the vendor-supplied patch for TeamCity.
  • Ensure agent polling protocol is secured.
References
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-63077.

URL Resource
https://www.jetbrains.com/privacy-security/issues-fixed/ Vendor Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-63077 US Government Resource
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-63077 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-63077 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-63077 vulnerability anywhere in the article.

  • security.nl
VS en Italië melden misbruik van kritiek lek in Jetbrains TeamCity-servers

Aanvallers maken actief misbruik van een kritieke kwetsbaarheid in Jetbrains TeamCity-servers waardoor systemen op afstand zijn over te nemen, zo melden de Amerikaanse en Italiaanse cyberagentschappen ... Read more

Published Date: Aug 06, 2026 (1 week, 3 days ago)
  • The Hacker News
CISA Flags TeamCity CVE-2026-63077 RCE Flaw Under Active Exploitation in the Wild

A newly patched security flaw impacting on-premise versions of JetBrains TeamCity has come under active exploitation in the wild, according to the U.S. Cybersecurity and Infrastructure Security Agency ... Read more

Published Date: Aug 06, 2026 (1 week, 4 days ago)
  • TheCyberThrone
CISA Adds Four Vulnerabilities to KEV Catalog Aug 6 2026

Four Newly Added KEV Entries Reinforce the Growing Focus on Enterprise Management, AI, Middleware, and DevSecOps PlatformsThe U.S. Cybersecurity and Infrastructure  Security Agency (CISA) has expanded ... Read more

Published Date: Aug 06, 2026 (1 week, 4 days ago)
  • The Cyber Express
CVE-2026-20316 Zero-Day Actively Exploited, Cisco Releases Fix

Cisco has released security updates for an actively exploited zero-day vulnerability, CVE-2026-20316, affecting Cisco Secure FMC (Secure Firewall Management Center) software. The flaw, disclosed on Ju ... Read more

Published Date: Jul 31, 2026 (2 weeks, 2 days ago)
  • The Cyber Express
CVE-2026-63077 Exposes TeamCity Servers to Unauthenticated RCE

A critical security flaw affecting TeamCity On-Premises has prompted administrators to update their servers immediately after researchers disclosed CVE-2026-63077, a vulnerability that could allow una ... Read more

Published Date: Jul 30, 2026 (2 weeks, 3 days ago)
  • TheCyberThrone
CISA Expands KEV Catalog with FortiOS and Arista VeloCloud Flaws

July 29, 2026The Cybersecurity and Infrastructure Security Agency (CISA) has expanded its Known Exploited Vulnerabilities (KEV) Catalog by adding two vulnerabilities affecting Fortinet FortiOS and Ari ... Read more

Published Date: Jul 29, 2026 (2 weeks, 5 days ago)
  • TheCyberThrone
CVE-2026-63077: JetBrains TeamCity RCE

Executive SummaryModern software development depends on CI/CD platforms to automate code building, testing, and deployment. These platforms hold privileged credentials, source code, signing certificat ... Read more

Published Date: Jul 28, 2026 (2 weeks, 5 days ago)

Results are limited to the first 20 news articles due to potential performance issues.

The following table lists the changes that have been made to the CVE-2026-63077 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Aug. 06, 2026

    Action Type Old Value New Value
    Changed SSVC {'id': 'CVE-2026-63077', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'active'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-08-05T17:46:04.215479Z'} {'id': 'CVE-2026-63077', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'active'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-07-27T00:00:00+00:00'}
  • Initial Analysis by [email protected]

    Aug. 05, 2026

    Action Type Old Value New Value
    Added CPE Configuration OR *cpe:2.3:a:jetbrains:teamcity:*:*:*:*:*:*:*:* versions up to (excluding) 2025.11.7 *cpe:2.3:a:jetbrains:teamcity:*:*:*:*:*:*:*:* versions from (including) 2026.1 up to (excluding) 2026.1.3
    Added Reference Type JetBrains s.r.o.: https://www.jetbrains.com/privacy-security/issues-fixed/ Types: Vendor Advisory
    Added Reference Type CISA-ADP: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-63077 Types: US Government Resource
  • CVE CISA KEV Update by 9119a7d8-5eab-497f-8521-727c672e3725

    Aug. 05, 2026

    Action Type Old Value New Value
    Added Date Added 2026-08-05
    Added Due Date 2026-08-05
    Added Required Action 2026-08-05
    Added Vulnerability Name 2026-08-05
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Aug. 05, 2026

    Action Type Old Value New Value
    Added Reference https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-63077
    Changed SSVC {'id': 'CVE-2026-63077', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-07-27T00:00:00+00:00'} {'id': 'CVE-2026-63077', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'active'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-08-05T17:46:04.215479Z'}
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Jul. 28, 2026

    Action Type Old Value New Value
    Changed SSVC {'id': 'CVE-2026-63077', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-07-27T17:30:44.951918Z'} {'id': 'CVE-2026-63077', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-07-27T00:00:00+00:00'}
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Jul. 27, 2026

    Action Type Old Value New Value
    Added SSVC {'id': 'CVE-2026-63077', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-07-27T17:30:44.951918Z'}
  • New CVE Received by [email protected]

    Jul. 27, 2026

    Action Type Old Value New Value
    Added Affected [{'vendor': 'JetBrains', 'product': 'TeamCity', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '2026.1.3, 2025.11.7', 'versionType': 'semver'}], 'defaultStatus': 'unaffected'}]
    Added Description In JetBrains TeamCity before 2026.1.3, 2025.11.7 unauthenticated remote code execution was possible via the agent polling protocol
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    Added CWE CWE-502
    Added Reference https://www.jetbrains.com/privacy-security/issues-fixed/
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CVSS
Vulnerability Scoring Details
Base CVSS Score: 9.8
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact