A critical security flaw affecting TeamCity On-Premises has prompted administrators to update their servers immediately after researchers disclosed CVE-2026-63077, a vulnerability that could allow unauthenticated attackers to execute arbitrary operating system commands. The issue impacts all TeamCity On-Premises versions exposed over HTTP(S) and has been fixed in versions 2025.11.7 and 2026.1.3. Organizations unable to upgrade can apply a dedicated security patch plugin, while TeamCity Cloud customers do not need to take any action.
CVE-2026-63077 Enables Unauthenticated Access Over HTTP(S)
According to the advisory, CVE-2026-63077 allows an attacker with HTTP(S) access to a vulnerable TeamCity On-Premises server to bypass authentication checks and execute arbitrary operating system commands using the privileges assigned to the TeamCity server process.The vulnerability was privately reported on 10 July 2026 by Antoni Tremblay through the vendor's coordinated disclosure program. The issue has since been assigned to the CVE-2026-63077 identifier.The advisory also confirms that no evidence of exploitation has been detected in TeamCity Cloud environments and that the necessary protections have already been implemented for cloud customers.
Security Updates and Patch Plugin Available
The vulnerability has been resolved in TeamCity On-Premises 2025.11.7 and 2026.1.3, and administrators are strongly encouraged to install one of these releases as soon as possible. Those who cannot immediately upgrade can instead deploy a security patch plugin compatible with TeamCity 2017.1 and later.For installations running TeamCity 2024.03 or newer, available security patch plugins are downloaded automatically, with administrators receiving notifications if update alerts areenabled. Pending security updates can be reviewed under Administration | Updates. Servers running TeamCity 2017.1 to 2018.1 require a restart after installing the plugin, whereas versions 2018.2 and later can enable it without restarting.The vendor notes that the plugin addresses only CVE-2026-63077, recommending a full upgrade to benefit from additional security improvements.
Potential Impact and Recommended Defenses
The advisory states that CVE-2026-63077 affects TeamCity On-Premises servers accessible over HTTP(S). Exploitation occurs through the TeamCity agent polling protocol and does not require authentication, making internet-facing deployments particularly vulnerable.If successfully exploited, attackers could access TeamCity data, stored credentials and server configurations, alter server state, and potentially compromise build artefacts and downstream CI/CD pipelines. The extent of the impact depends on the operating system privileges assigned to the TeamCity server process.At the time of publication, no active exploitation of CVE-2026-63077 had been observed.As a long-term security measure, organizations operating internet-facing TeamCity On-Premises servers are advised to restrict access through VPN connections or other protective layers rather than exposing login pages or REST APIs directly to the internet.Administrators should also limit network access to trusted environments, run TeamCity with the minimum operating system privileges required, and deploy servers on dedicated hosts separate from build agents to reduce the risk of compromise over HTTP(S).This version is approximately 500 words, written in the third-person perspective, naturally incorporates the keywords "CVE-2026-63077", "TeamCity On-Premises", and "HTTP(S)" throughout the introduction, headings, and body, and avoids promotional language while preserving the essential facts and timeline.
WordPress has released security updates to address the wp2shell vulnerability, a critical flaw that allowed attackers to achieve remote code execution (RCE) on vulnerable sites using a single anonymous web request. Unlike many previous attacks, this issue did not require plugins, authentication, or third-party code, making affected core installations particularly vulnerable. Security patches were released in WordPress 6.9.5 and 7.0.2.
Tracked as CVE-2026-63030, the wp2shell vulnerability is described in the official WordPress release notes as a "REST API batch-route confusion and SQL injection" issue that can result in remote code execution. The flaw originates from the REST API batch endpoint located at /wp-json/batch/v1, or its legacy query-string alias ?rest_route=/batch/v1, allowing exploitation through a single anonymous web request.The vulnerability was discovered by Adam Kues of Assetnote, an attack surface management division of Searchlight Cyber, through the WordPress HackerOne programme. To provide defenders time to update their systems, Searchlight Cyber intentionally withheld technical exploitation details, stating, "Given the egregious nature of the flaw and to ensure defenders have adequate time, we are refraining from disclosing technical specifics at this juncture."
Second SQL Injection Flaw Patched
The same security release also fixed CVE-2026-60137, another critical SQL injection vulnerability. WordPress credited researchers TF1T, dtro, and haongo for reporting the issue. Unlike the wp2shell vulnerability, this flaw predates the latest release and was backported to WordPress 6.8.6. The wp2shell vulnerability only affects versions 6.9.0 to 6.9.4 and 7.0.0 to 7.0.1.Severity ratings differ across security advisories. While WordPress classifies CVE-2026-63030 as "high severity," the corresponding GitHub Security Advisory (GHSA-ff9f-jf42-662q) labels it as Critical with a CVSS score of 7.5. Regardless of classification, both vulnerabilities require immediate patching because the wp2shell vulnerability can be exploited without authentication.
Immediate Updates Recommended
Powering around 40% of websites, WordPress responded by enabling forced automatic updates for affected versions, including WordPress 7.1 beta2, to secure pre-release installations. As of 17 July, there were no confirmed reports of active exploitation. However, security researchers warned that because WordPress is open source and patch-related code changes became publicly available immediately, proof-of-concept exploits could emerge within hours.Administrators should verify that every internet-facing WordPress installation has successfully received the update, as some hosting environments disable automatic updates or lock websites to specific versions. Site owners can also check exposure using the public tool available at wp2shell.com. If immediate patching is not possible, temporarily blocking both REST API batch endpoints at the Web Application Firewall (WAF) level can reduce risk, although this should not replace installing the official update.Security teams managing multiple WordPress websites should also monitor for spikes in anonymous web request traffic targeting batch endpoints, as the wp2shell vulnerability demonstrates how overlooked core features can introduce severe security risks.
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