{"id":"CVE-2026-63077","published":"2026-07-27T17:16:38Z","modified":"2026-10-24T13:10:00Z","title":"JetBrains TeamCity Deserialization of Untrusted Data Vulnerability","vendor":"JetBrains","product":"TeamCity","tier":"core","eol":null,"description":{"text":"In JetBrains TeamCity before 2026.1.3, 2025.11.7 unauthenticated remote code execution was possible via the agent polling protocol","provenance":"source","from":"NVD"},"summary":{"text":"JetBrains TeamCity, prior to versions 2026.1.3 and 2025.11.7, contains a deserialization of untrusted data flaw in its agent polling protocol. An attacker with network access to the TeamCity server can achieve unauthenticated remote code execution, requiring no credentials or user interaction.","provenance":"ai","model":"claude-haiku-5-5","generatedAt":"2026-10-23T07:01:54Z"},"cvss":{"score":9.8,"severity":"CRITICAL","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","provenance":"source","from":"NVD"},"epss":{"score":0.93558,"percentile":0.99841,"date":"2026-10-30","provenance":"source"},"kev":{"dateAdded":"2026-08-05","dueDate":"2026-08-08","ransomware":true,"requiredAction":"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.","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","provenance":"source"},"vulncheckKev":{"dateAdded":"2026-08-05","exploitedFirstSeen":"2026-08-05","ransomware":true,"evidence":[{"url":"https://previdian.com/CVE-2026-63077","date":"2026-08-05"},{"url":"https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json","date":"2026-08-05"},{"url":"https://www.cyber.gov.au/about-us/view-all-content/alerts-and-advisories/active-exploitation-of-a-software-development-platform-within-australia","date":"2026-08-24"},{"url":"https://www.recordedfuture.com/blog/august-2026-cve-landscape","date":"2026-09-08"}],"evidenceTotal":4,"provenance":"source"},"exploited":true,"otx":{"pulseCount":45,"pulses":[{"name":"Actively_Exploited_Kev | Oct 31, 2026","url":"https://otx.alienvault.com/pulse/6ae4aefab0c2191cecd41862","created":"2026-10-30"},{"name":"Actively_Exploited_Kev | Oct 30, 2026","url":"https://otx.alienvault.com/pulse/6ae35d889ea92b4ce19c2680","created":"2026-10-29"},{"name":"Actively_Exploited_Kev | Oct 29, 2026","url":"https://otx.alienvault.com/pulse/6ae20c1db17e7057ae7d9ad1","created":"2026-10-28"},{"name":"Actively_Exploited_Kev | Oct 28, 2026","url":"https://otx.alienvault.com/pulse/6ae0ba7e0e2a97ff7b218819","created":"2026-10-27"},{"name":"Actively_Exploited_Kev | Oct 27, 2026","url":"https://otx.alienvault.com/pulse/6adf68b85c3e852f3c111d18","created":"2026-10-26"},{"name":"Actively_Exploited_Kev | Oct 24, 2026","url":"https://otx.alienvault.com/pulse/6adb740e397c3ad4799aa4cd","created":"2026-10-23"},{"name":"Actively_Exploited_Kev | Oct 23, 2026","url":"https://otx.alienvault.com/pulse/6ada236fcfba2dfa730ea482","created":"2026-10-22"},{"name":"Actively_Exploited_Kev | Oct 22, 2026","url":"https://otx.alienvault.com/pulse/6ad8d33a077cbb5cab524d80","created":"2026-10-21"},{"name":"Actively_Exploited_Kev | Oct 21, 2026","url":"https://otx.alienvault.com/pulse/6ad78130c4d1ac2be83a8b6d","created":"2026-10-20"},{"name":"Actively_Exploited_Kev | Oct 20, 2026","url":"https://otx.alienvault.com/pulse/6ad62f63c24a405a3423cc13","created":"2026-10-19"}],"provenance":"machine"},"cwes":[{"id":"CWE-502","name":"Deserialization of Untrusted Data"}],"references":[{"url":"https://www.jetbrains.com/privacy-security/issues-fixed/","tags":["Vendor Advisory"]},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-63077","tags":["US Government Resource"]}],"techniques":[{"id":"T1190","name":"Exploit Public-Facing Application","tactics":["initial-access"],"provenance":"ai","basis":"ai-mapping","bases":["ai-mapping"],"basisDetail":"claude-haiku-5-5: Unauthenticated network exploit against public-facing TeamCity server","mappingType":"exploitation_technique","evidence":[{"from":"description","quote":"unauthenticated remote code execution was possible via the agent polling protocol","start":49,"end":130}],"model":"claude-haiku-5-5","confidence":"medium","confidenceNote":"AI-mapped from the description (quote-validated, not expert-reviewed)"},{"id":"T1059","name":"Command and Scripting Interpreter","tactics":["execution"],"provenance":"ai","basis":"ai-mapping","bases":["ai-mapping"],"basisDetail":"claude-haiku-5-5: Direct remote code execution is the primary impact","mappingType":"primary_impact","evidence":[{"from":"description","quote":"unauthenticated remote code execution was possible","start":49,"end":99}],"model":"claude-haiku-5-5","confidence":"medium","confidenceNote":"AI-mapped from the description (quote-validated, not expert-reviewed)"}],"reports":[],"affected":[],"advisories":[],"euvd":{"id":"EUVD-2026-49369","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-49369","exploited":true,"exploitedSince":"2026-08-05","provenance":"source"},"exploits":[],"exploitSources":{"pocGithub":{"count":7,"skipped":0,"earliest":"2026-07-30","earliestUrl":"https://github.com/unveiledhistory49/teamcity-cve-2026-63077-remediation","repos":[{"name":"sfewer-r7/CVE-2026-63077","url":"https://github.com/sfewer-r7/CVE-2026-63077","stars":20,"created":"2026-08-07"},{"name":"unveiledhistory49/teamcity-cve-2026-63077-remediation","url":"https://github.com/unveiledhistory49/teamcity-cve-2026-63077-remediation","stars":0,"created":"2026-07-30"},{"name":"BoredHackerBlog/teamcity-CVE-2026-63077-pcap","url":"https://github.com/BoredHackerBlog/teamcity-CVE-2026-63077-pcap","stars":0,"created":"2026-08-08"},{"name":"AnggaTechI/CVE-2026-63077","url":"https://github.com/AnggaTechI/CVE-2026-63077","stars":0,"created":"2026-08-08"},{"name":"bakos-sandor-nx/teamcity-cve-2026-63077-remediation","url":"https://github.com/bakos-sandor-nx/teamcity-cve-2026-63077-remediation","stars":0,"created":"2026-08-19"}]},"metasploit":[{"name":"JetBrains TeamCity Agent Polling Unauthenticated Remote Code Execution","module":"exploit/multi/http/jetbrains_teamcity_rce_cve_2026_63077","type":"exploit","disclosureDate":"2026-07-27","url":"https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/multi/http/jetbrains_teamcity_rce_cve_2026_63077.rb"}],"nuclei":[{"id":"CVE-2026-63077","name":"JetBrains TeamCity < 2026.1.3, 2025.11.7 - Remote Code 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