JetBrains TeamCity's Deserialization of Untrusted Data Allows Unauthenticated Remote Attackers to Execute Arbitrary Code on the CI/CD Server; CISA's August 8th KEV Deadline Has Passed

Last refreshed2026-09-27

Status: KEV | Advisory ID: CVE-2026-63077

Key Details

CVE	CVE-2026-63077
Vulnerability Name	JetBrains TeamCity Deserialization of Untrusted Data Vulnerability
CVSS Score / Version	9.8 (Critical) / CVSS v3.1
Updated	2026-09-22
CVSS Vector	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`
CVSS Prose	attack vector is network; attack complexity is low; privileges required is none; user interaction is none; scope is unchanged; confidentiality impact is high; integrity impact is high; availability impact is high.
Affected products	JetBrains TeamCity
Exploitation status	Listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, indicating confirmed active exploitation.
Classified as	CWE-502 (Deserialization of Untrusted Data)
KEV listing	Added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2026-08-05.
Exploitation prediction (EPSS)	9.76% probability of exploitation in the next 30 days (95% percentile) -- FIRST.org's EPSS model.
Federal remediation deadline	2026-08-08 (CISA KEV, Binding Operational Directive).

Affected Products, Subsystems & Sectors

Vendor	Product	Affected Versions	Patch Status
JetBrains	TeamCity

Vendor

Product

Affected Versions

Patch Status

JetBrains

TeamCity

Subsystems	General OT
Sectors	Multiple

What to Know

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

What to Do

Monitor JetBrains's web page for any future patch releases.

References

Source	Reference
NVD	https://nvd.nist.gov/vuln/detail/CVE-2026-63077
CVE	https://www.cve.org/CVERecord?id=CVE-2026-63077

Source

Reference

NVD

https://nvd.nist.gov/vuln/detail/CVE-2026-63077

CVE

https://www.cve.org/CVERecord?id=CVE-2026-63077

KEV Required Action

Field	Value
KEV Link	https://www.cisa.gov/known-exploited-vulnerabilities-catalog
Date Added to KEV	2026-08-05
Required Action Due Date	2026-08-08
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.

Field

Value

KEV Link

https://www.cisa.gov/known-exploited-vulnerabilities-catalog

Date Added to KEV

2026-08-05

Required Action Due Date

2026-08-08

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.