What is the CVSS score of CVE-2026-63077?

CVE-2026-63077 has a CVSS 3.1 base score of 9.8 (Critical). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. EPSS exploitation probability: 0.6%.

Is there a public PoC exploit available for CVE-2026-63077?

Yes, a public proof-of-concept exploit is available for CVE-2026-63077. Prioritise patching immediately. EPSS: 0.6%.

Is there a patch available for CVE-2026-63077?

Yes, a patch is available for CVE-2026-63077. Update the affected software to the latest version immediately.

Teamcity CVE-2026-63077

EUVD-2026-49369 CRITICAL

Deserialization of Untrusted Data (CWE-502)

2026-07-27 JetBrains

GHSA-94gx-v738-fx9w

RCE Deserialization Teamcity JetBrains

9.8

CVSS 3.1 · Vendor: JetBrains

View

Vulnerability Assessment

Weakness

CWE

CWE-502

OWASP Top 10:2025

A08:2025 - Software or Data Integrity Failures

ASVS 5.0

V1 - Encoding and Sanitization Safe deserialization, type allowlists

MITRE ATT&CK

2 techniques across 2 tactics: Execution, Initial Access

The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up.

Act Now Prioritize within 24-48h. Why: In CISA KEV with patch available.

Exploited in the wild (CISA KEV) 2 public PoCs + 1 unverified Patch available 0.6% exploitation probability (EPSS)

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AnalysisAIv1 – Jul 27, 2026

Remote code execution in JetBrains TeamCity before 2026.1.3 and 2025.11.7 allows unauthenticated attackers to execute arbitrary code via deserialization of untrusted data in the agent polling protocol. The vulnerability carries a CVSS 9.8 score and poses immediate risk to any exposed TeamCity instance. No public exploit or active exploitation has been confirmed at the time of analysis.

Affected VersionsENISA

TeamCity 0 <2026.1.3, 2025.11.7

Affected Packages

euvd teamcity_0_2026_1_3 no fix

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 1 package in euvd

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

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Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

Vendor (JetBrains) PRIMARY 9.8 CRITICAL

AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Primary rating from Vendor (JetBrains) · only source for this CVE.

CVSS VectorVendor: JetBrains

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Added to CISA KEV

Aug 05, 2026 - 18:03 CISA

Patch available

Jul 27, 2026 - 18:02 EUVD

CVE Published

Jul 27, 2026 - 16:44 cve.org

CRITICAL 9.8

DescriptionCVE.org

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

Articles & Coverage 1

POC JetBrains TeamCity On-Premises CVE-2026-63077: PoC Exploit and 48-Hour Emergency Hardening Runbook Aug 04, 2026

Latest POC

2 public PoC links from github, metasploit, nuclei, plus 1 unverified

Threat Model

4 threats: Elevation of Privilege, Tampering, Information Disclosure and 1 more

3-step attack chain with trust boundaries and controls

Full threat model - attack chain, trust boundaries, controls per stage and evidence - is part of the Pro and Business plans.

Threat Intelligence Overview

Threat Score

5.0/10

Composite threat intelligence

EPSS Score

0.6%

Top 53% exploitable

Threat Intel

1 sources

Social Media

Sightings

Data Quality

9 sources

Confidence: High

EUVD

NVD

CVE.org

CISA KEV

EPSS

Vulnrichment NEWS POC (2) CIRCL

GitHub

VulDB

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue

Severity CRITICAL

CISA KEV Yes

Public POC Yes

EPSS 0.6%

Patch available Yes

Active threat Yes

Deciding rule

In CISA KEV with patch available

What every action level means

Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.

Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.

This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.

This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.

Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived

Scheduled

Exploitation

None

System Exposure· derived

Open

Automatable

Yes

Human Impact· derived

High

Technical Impact

Total

Priority Score

135

Low Medium High Critical

KEV: +50

EPSS: +1

CVSS: +49

PoC: +20

Weaponized: +15

Threat intel: 0

Gov advisory: 0

Attack Technique

Insecure Deserialization CRITICAL

Insecure deserialization occurs when an application converts serialized data (a stream of bytes representing an object's state) back into a living object without proper validation.

Remote Code Execution CRITICAL

Remote Code Execution represents the critical moment when an attacker successfully runs arbitrary code on a target system without physical access.