CVE-2026-30921
Hackerbay Oneuptime ≤ 10.0.20
Raw vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:HSummary
CVE-2026-30921 is a critical-severity Exposed Dangerous Method or Function (CWE-749) vulnerability in Hackerbay Oneuptime. Its CVSS base score is 9.9 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 37th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified map to AC-3 (Access Enforcement) and AC-6 (Least Privilege) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-30921 is a critical remote code execution (RCE) vulnerability in OneUptime, an open-source solution for monitoring and managing online services. It affects versions prior to 10.0.20, specifically the Synthetic Monitors feature, where low-privileged project users can submit custom Playwright code executed on the oneuptime-probe service. This code runs inside Node.js's vm module but receives live host Playwright objects, such as browser and page, bypassing traditional sandbox escapes. Attackers can directly invoke methods like browser.browserType().launch() to spawn arbitrary executables on the probe host or container. The vulnerability is rated 9.9 on the CVSS 3.1 scale (AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H) and maps to CWE-749 (Exposed Dangerous Method or Function).
Low-privileged project users with access to submit custom Playwright scripts for Synthetic Monitors can exploit this vulnerability over the network with low complexity and no user interaction required. By crafting malicious code that leverages the provided Playwright objects, attackers achieve server-side RCE on the oneuptime-probe service, enabling full compromise of the host or container, including high confidentiality, integrity, and availability impacts due to the changed scope.
The vulnerability is fixed in OneUptime version 10.0.20. For full details on the patch and mitigation steps, refer to the GitHub security advisory at https://github.com/OneUptime/oneuptime/security/advisories/GHSA-4j36-39gm-8vq8.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-10434
Vulnerability Data
OneUptime is a solution for monitoring and managing online services. Prior to 10.0.20, OneUptime Synthetic Monitors allow low-privileged project users to submit custom Playwright code that is executed on the oneuptime-probe service. In the current implementation, this untrusted code is…
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run inside Node's vm and is given live host Playwright objects such as browser and page. This creates a distinct server-side RCE primitive: the attacker does not need the classic this.constructor.constructor(...) sandbox escape. Instead, the attacker can directly use the injected Playwright browser object to reach browser.browserType().launch(...) and spawn an arbitrary executable on the probe host/container. This vulnerability is fixed in 10.0.20.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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- 4 hardening rules · 2 OS baselines
V8.2.1
Mitigating Controls (NIST 800-53 r5) AI
Access enforcement directly stops unauthorized callers from invoking dangerous API methods or functions.
Least privilege restricts which users or processes may reach dangerous methods, limiting exposure.
Least functionality removes or disables non-essential dangerous methods from the exposed interface altogether.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Enforcing least-privilege authorization directly prevents unrestricted dangerous API methods.
Secure SDLC practices stop developers from exposing dangerous functions in the first place.
Vulnerability identification processes will surface exposed dangerous methods during assessment.
Logical access controls at the network/environment layer can limit reachability of exposed functions.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing can detect exposed dangerous functions, but does not prevent their initial introduction.
Restricting privileged utility programs reduces exposure of dangerous functions, but does not eliminate the underlying weakness.
Privileged access rights limit who can invoke dangerous methods, but do not address whether the method itself should exist.
Secure development life cycle requires removal or protection of dangerous APIs during design and coding.
Application security requirements can mandate that dangerous methods are not exposed in interfaces.
Secure architecture principles discourage exposing dangerous functions, but do not guarantee their absence.
Hardening callouts derived
Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).
Ubuntu 22.04 (3 rules)
- V-260559 Ubuntu 22.04 LTS must ensure only users who need access to security functions are part of sudo group. prevents CWE-749
- V-260529 Ubuntu 22.04 LTS must be configured so that remote X connections are disabled, unless to fulfill documented and validated mission requirements. prevents CWE-749
- V-260557 Ubuntu 22.04 LTS must be configured to use AppArmor. prevents CWE-749
Ubuntu 24.04 (1 rule)
- V-270748 Ubuntu 24.04 LTS must ensure only users who need access to security functions are part of sudo group. prevents CWE-749