# CVE-2026-63077 — JetBrains TeamCity

> As of 2026-07-28, CVE-2026-63077 is a CRITICAL-severity vulnerability in JetBrains TeamCity, CVSS v3.1 9.8, EPSS 0.6% (47.3th percentile). Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2026-63077, most recently “CVE-2026-63077: Unauthenticated RCE in JetBrains TeamCity On-Premises via Agent Polling Protocol”.

**Last updated:** 2026-07-28

## What is CVE-2026-63077?

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

The record classifies CVE-2026-63077 under weakness class [CWE-502](https://cwe.mitre.org/data/definitions/502.html). Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction, and has high impact on confidentiality, integrity, availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 57 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 9.8 — CRITICAL (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **EPSS (FIRST):** 0.6% probability of exploitation in the next 30 days, higher than 47.3% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 6.8/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-07-27, last modified 2026-07-28

## Is CVE-2026-63077 being exploited?

No public exploitation evidence for CVE-2026-63077 is recorded in the sources Threadlinqs tracks — CISA KEV, Exploit-DB, public proof-of-concept repositories and ProjectDiscovery Nuclei — as of 2026-07-28. That is an absence of evidence in those feeds, not a guarantee that the vulnerability is unexploited.

## Affected products and versions

- **JetBrains**: TeamCity

## How to fix CVE-2026-63077

No vendor patch reference has been recorded for CVE-2026-63077 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

## Threat activity tracking CVE-2026-63077

1 tracked threat in the Threadlinqs corpus references CVE-2026-63077, either in the campaign’s CVE list or as an indicator on the campaign record.

- [CVE-2026-63077: Unauthenticated RCE in JetBrains TeamCity On-Premises via Agent Polling Protocol](https://intel.threadlinqs.com/threat/TL-2026-1747) — CRITICAL · 2026-07-28

## Sources

Enriched from CVE.org, NVD, FIRST EPSS, GitHub Security Advisories. Last verified by Threadlinqs on 2026-07-28. This product uses the NVD API but is not endorsed or certified by the NVD.

**Other references**

- [jetbrains.com](https://www.jetbrains.com/privacy-security/issues-fixed/)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-63077
Full detection coverage and IOCs for threats exploiting CVE-2026-63077 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp