VulnerabilityPublished 18 Mar 2026

CVE-2026-32723: nyariv SandboxJS · Race Condition

Affects nyariv SandboxJSSource CVE Database V5

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Not known to be exploited · CVSS 4.8 Medium : upgrade to 0.8.35 when convenient.

Data as of 31 Oct 2026, 08:20 UTC

CVSS 4.0 base score

4.8Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.1% chance of exploitation in 30 days – higher than 4% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 0.8.35

CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

Attack Vector: Local
Attack Complexity: Low
Attack Requirements: None
Privileges Required: Low
User Interaction: None
Vulnerable system confidentiality: None
Vulnerable system integrity: None
Vulnerable system availability: Low
Subsequent system confidentiality: None
Subsequent system integrity: None
Subsequent system availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Local: The vulnerable system is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or through terminal emulation (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., using social engineering techniques to trick a legitimate user into opening a malicious document).
Attack Complexity: Low: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
Privileges Required: Low: The attacker requires privileges that provide basic capabilities that are typically limited to settings and resources owned by a single low-privileged user. Alternatively, an attacker with Low privileges has the ability to access only non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: None: There is no loss of confidentiality within the Vulnerable System.
Vulnerable system integrity: None: There is no loss of integrity within the Vulnerable System.
Vulnerable system availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the Vulnerable System are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the Vulnerable System.
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 18 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade SandboxJS and nyariv/sandboxjs to 0.8.35.

Affected software

Product	Affected	Fixed in
nyarivSandboxJS	Affected <0.8.35	Fixed in 0.8.35
npmnyariv/sandboxjs`pkg:npm/nyariv/sandboxjs`Other threats	Affected <0.8.35	Fixed in 0.8.35

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

To mitigate CVE-2026-32723, organizations should immediately upgrade SandboxJS to version 0.8.35 or later, where the race condition is fixed by isolating tick states per sandbox or implementing proper synchronization mechanisms. For environments where immediate upgrade is not feasible, consider isolating sandboxes at the process or container level to prevent shared state interference. Implement strict resource monitoring and limits at the host or container orchestration level to detect and contain abnormal execution time or CPU usage. Review and harden sandbox configuration to minimize concurrency risks, such as limiting the number of concurrent sandboxes or disabling timer-based callbacks if not essential. Conduct thorough testing of sandbox behavior under concurrent loads to identify potential synchronization issues. Additionally, maintain vigilant logging and alerting on execution quota breaches or watchdog bypass attempts to enable rapid incident response. Avoid sharing global mutable state across sandboxes and adopt thread-safe or atomic operations for any shared resources in sandbox implementations.

Description

CVE-2026-32723 is a medium-severity race condition vulnerability in SandboxJS versions prior to 0.8.35. It arises from improper synchronization of a shared global tick state used to enforce execution quotas across concurrent sandboxes. An attacker controlling one sandbox can manipulate the global tick state to bypass the execution quota/watchdog of another sandbox, potentially allowing excessive or unauthorized code execution. Exploitation requires local access with low privileges but no user interaction. The vulnerability affects multi-tenant or concurrent sandbox environments using vulnerable SandboxJS versions. No known exploits are currently reported in the wild. The issue is fixed in version 0.8.

Impact

The primary impact of CVE-2026-32723 is the potential bypass of execution quotas and watchdog timers in SandboxJS, which can lead to denial of service or resource exhaustion within multi-tenant sandbox environments. Attackers controlling one sandbox instance can manipulate the shared global tick state to extend their execution time beyond intended limits, potentially causing performance degradation or instability in the host system. This undermines the security guarantees of sandbox isolation, increasing the risk of one tenant affecting others in shared environments. While it does not directly lead to code execution outside the sandbox or privilege escalation, the ability to bypass execution limits can facilitate further attacks or disrupt service availability. Organizations relying on SandboxJS for secure code execution in cloud services, web hosting, or multi-tenant platforms may face increased risk of service disruption or abuse. The vulnerability’s medium CVSS score reflects moderate impact due to the local attack vector and limited scope but highlights the importance of proper synchronization in sandbox implementations.

CWE-362Concurrent Execution using Shared Resource with Improper Synchronization (Race Condition) (opens in a new tab)
Class weaknessLikelihood of exploit: MediumOWASP Top 10 A06:2025: Insecure Design (opens in a new tab)
The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.
Architecture and Design
In languages that support it, use synchronization primitives. Only wrap these around critical code to minimize the impact on performance.
Architecture and Design
Use thread-safe capabilities such as the data access abstraction in Spring.
Architecture and Design
Minimize the usage of shared resources in order to remove as much complexity as possible from the control flow and to reduce the likelihood of unexpected conditions occurring.
OWASP Cheat Sheets
Abuse Case (opens in a new tab)
Secure Design Principles (opens in a new tab)
OWASP ASVS 4.0.3
V1.11.2 (opens in a new tab)
Attack patterns
Leveraging Time-of-Check and Time-of-Use (TOCTOU) Race Conditions (opens in a new tab)
Leveraging Race Conditions (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 26 Mar 2026, 01:12 UTC

WeaknessesCWE-362

Technical details

References

Community reviews

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