{"id":2038,"date":"2026-07-28T09:39:31","date_gmt":"2026-07-28T09:39:31","guid":{"rendered":"https:\/\/thedigitalfortress.us\/?p=2038"},"modified":"2026-07-28T09:39:31","modified_gmt":"2026-07-28T09:39:31","slug":"critical-teamcity-flaw-could-let-attackers-run-os-commands-without-logging-in","status":"publish","type":"post","link":"https:\/\/thedigitalfortress.us\/?p=2038","title":{"rendered":"Critical TeamCity Flaw Could Let Attackers Run OS Commands Without Logging In"},"content":{"rendered":"
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\ue804<\/i>Ravie Lakshmanan<\/span>\ue802<\/i>Jul 28, 2026<\/span><\/span>Vulnerability \/ Enterprise Security<\/span><\/p>\n<\/div>\n

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<\/a><\/div>\n

JetBrains is urging customers<\/a> of on-premise versions of TeamCity to update to the latest version following the discovery of a critical security issue that could result in arbitrary code execution.<\/p>\n

The vulnerability, assigned CVE-2026-63077<\/strong> (CVSS score: 9.8), affects all TeamCity On-Premises versions. It has been addressed in versions 2025.11.7 and 2026.1.3. TeamCity Cloud instances have already been updated. JetBrains has credited Antoni Tremblay with discovering and reporting the flaw on July 10, 2026.<\/p>\n

\u00abIf exploited, this flaw may enable an unauthenticated attacker with HTTP(S) access to a TeamCity server to bypass authentication checks and execute arbitrary operating system commands with the privileges of the TeamCity server process,\u00bb JetBrains said.<\/p>\n

The flaw allows unauthenticated remote code execution via the agent polling protocol to sidestep authentication checks and achieve command execution. Depending on the privileges granted to the TeamCity server process, a successful compromise can lead to the exposure of TeamCity data, configurations, and stored credentials, or modification of server state.<\/p>\n

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\"Cybersecurity\"<\/a><\/div>\n<\/div>\n

Besides releasing versions 2025.11.7 and 2026.1.3, JetBrains has released a security patch plugin<\/a> for versions 2017.1+ so that customers who are unable to apply an update can still patch their environments. There is no evidence to indicate that the flaw has been exploited in the wild.<\/p>\n

\u00abThe security patch plugin will address only the vulnerability described above (CVE-2026-63077),\u00bb JetBrains cautioned. \u00abWe always recommend upgrading your server to the latest version to benefit from many other security updates.\u00bb<\/p>\n

As best practices, customers are advised to consider requiring VPN connections or implementing an extra layer of security to prevent unauthorized access to internet-facing TeamCity servers.<\/p>\n

\u00abEven exposing the TeamCity login screen or REST API can provide attackers with potential entry points to exploit newly disclosed vulnerabilities,\u00bb it added.<\/p>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

\ue804Ravie Lakshmanan\ue802Jul 28, 2026Vulnerability \/ Enterprise Security JetBrains is urging customers of on-premise versions of TeamCity to update to the latest version following the discovery of a critical security issue…<\/p>\n","protected":false},"author":1,"featured_media":2039,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[622,195,58,70,1643,1774,2755],"class_list":["post-2038","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-uncategorized","tag-attackers","tag-commands","tag-critical","tag-flaw","tag-logging","tag-run","tag-teamcity"],"_links":{"self":[{"href":"https:\/\/thedigitalfortress.us\/index.php?rest_route=\/wp\/v2\/posts\/2038","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/thedigitalfortress.us\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/thedigitalfortress.us\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/thedigitalfortress.us\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/thedigitalfortress.us\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2038"}],"version-history":[{"count":0,"href":"https:\/\/thedigitalfortress.us\/index.php?rest_route=\/wp\/v2\/posts\/2038\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/thedigitalfortress.us\/index.php?rest_route=\/wp\/v2\/media\/2039"}],"wp:attachment":[{"href":"https:\/\/thedigitalfortress.us\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2038"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/thedigitalfortress.us\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2038"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/thedigitalfortress.us\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2038"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}