How severe is CVE-2026-63077?

CVE-2026-63077 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-63077 being actively exploited?

Yes. CVE-2026-63077 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2026-08-05, which means active exploitation has been confirmed. It should be prioritised for remediation.

What products are affected by CVE-2026-63077?

CVE-2026-63077 affects Jetbrains Teamcity. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-63077?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.

When was CVE-2026-63077 published?

CVE-2026-63077 was published on 2026-07-27 and last updated on 2026-08-06.

CVE-2026-63077

CVE-2026-63077 is a critical-severity vulnerability in Jetbrains Teamcity with a CVSS 3.x base score of 9.8. It is listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, confirming it has been exploited in the wild (added 2026-08-05). The underlying weakness is classified as CWE-502.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
EPSS exploit prediction: 11% (95th percentile)
Actively exploited: Yes — listed in CISA KEV (added 2026-08-05)
Weakness: CWE-502
Affected product: Jetbrains Teamcity
Published: 2026-07-27
Last modified: 2026-08-06

Description

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

Frequently asked questions

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
How severe is CVE-2026-63077?: CVE-2026-63077 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-63077 being actively exploited?: Yes. CVE-2026-63077 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2026-08-05, which means active exploitation has been confirmed. It should be prioritised for remediation.
What products are affected by CVE-2026-63077?: CVE-2026-63077 affects Jetbrains Teamcity. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-63077?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.
When was CVE-2026-63077 published?: CVE-2026-63077 was published on 2026-07-27 and last updated on 2026-08-06.

References

Affected products (1)

cpe:2.3:a:jetbrains:teamcity:*:*:*:*:*:*:*:*

More vulnerabilities in Jetbrains Teamcity

CVE-2024-27198 — Critical (CVSS 9.8): In JetBrains TeamCity before 2023.11.4 authentication bypass allowing to perform admin actions was possible
CVE-2024-23917 — Critical (CVSS 9.8): In JetBrains TeamCity before 2023.11.3 authentication bypass leading to RCE was possible
CVE-2023-42793 — Critical (CVSS 9.8): In JetBrains TeamCity before 2023.05.4 authentication bypass leading to RCE on TeamCity Server was possible
CVE-2022-25263 — Critical (CVSS 9.8): JetBrains TeamCity before 2021.2.3 was vulnerable to OS command injection in the Agent Push feature configuration.
CVE-2022-24340 — Critical (CVSS 9.8): In JetBrains TeamCity before 2021.2.1, XXE during the parsing of the configuration file was possible.
CVE-2022-24331 — Critical (CVSS 9.8): In JetBrains TeamCity before 2021.1.4, GitLab authentication impersonation was possible.

All CVEs affecting Jetbrains Teamcity →

Other CWE-502 (Deserialization of Untrusted Data) vulnerabilities

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CVE-2026-43633 — Critical (CVSS 10.0): HestiaCP versions 1.9.0 through 1.9.4 contain a deserialization vulnerability in the web terminal component caused by a…
CVE-2026-33819 — Critical (CVSS 10.0): Deserialization of untrusted data in Microsoft Bing allows an unauthorized attacker to execute code over a network.

Browse all CWE-502 (Deserialization of Untrusted Data) vulnerabilities →

Threat intelligence

Threat-intel indicators referencing this CVE:

8.211.195.173 (ipv4-addr)