CVE-2026-57736: HubSpot Sensitive Data Exposure Vulnerability (CVSS 7.4)

Technical summary

CVE-2026-57736 is classified as an Insertion of Sensitive Information Into Sent Data vulnerability (CWE-201). The flaw enables authenticated attackers to retrieve sensitive data embedded within network communications or API responses. The vulnerability affects HubSpot through version 11.3.51 and requires valid user credentials to exploit (PR:L in the CVSS vector). The attack is network-accessible with low complexity, and the impact spans confidentiality, integrity, and availability across trust boundaries (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:L, scoring 7.4 HIGH).

Business impact

Data leakage of this nature exposes HubSpot users to customer information disclosure, proprietary business data exposure, and potential regulatory compliance violations depending on what sensitive data is embedded and retrieved. For organizations relying on HubSpot for CRM operations, this could compromise customer trust, trigger breach notification obligations, and create audit and legal complications. The requirement for authentication limits exposure to insider threats and compromised accounts rather than anonymous internet access.

Affected systems

HubSpot deployments running version 11.3.51 and earlier are vulnerable. The vendor product information is not enumerated in available data; verify your HubSpot instance version immediately through the administrative interface or API to determine exposure. Note that the advisory does not specify whether all HubSpot service tiers or deployment models are affected equally; confirm applicability to your specific deployment.

Exploitability

Exploitation requires valid HubSpot user credentials, which significantly raises the bar compared to unauthenticated attacks. However, in environments with weak access controls, shared accounts, or compromised user tokens, the risk increases materially. The low complexity of the attack (AC:L) and network accessibility mean that any authenticated user meeting the requirements can trigger it without specialized tools or techniques. The vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog, indicating no confirmed active exploitation in the wild at the time of publication.

Remediation

Update HubSpot to a patched version above 11.3.51. Coordinate with your HubSpot deployment team or account manager to confirm release schedules and availability of security updates. Pending patching, enforce strict access controls on HubSpot user accounts, implement principle of least privilege for API token distribution, and monitor for suspicious data retrieval patterns in logs.

Patch guidance

Verify the latest patched HubSpot version available in your deployment channel (cloud-hosted, on-premise, or partner-managed). HubSpot typically delivers updates automatically for cloud deployments; review your admin dashboard for available security updates and deploy them during a maintenance window. For on-premise or custom deployments, contact HubSpot support to confirm the specific version that remediates CVE-2026-57736 and obtain the upgrade instructions. Validate post-patch that sensitive data is no longer retrievable through standard API or UI workflows.

Detection guidance

Review HubSpot audit logs and API access patterns for unusual data retrieval requests, particularly from user accounts with minimal legitimate business reason to access sensitive embedded data. Monitor for repeated failed API calls followed by successful extraction attempts, which may indicate reconnaissance or exploitation. Implement alerts on access to sensitive data fields or endpoints that serve embedded information. Check for abnormal geographic or temporal patterns in user authentication and API calls from authenticated accounts.

Why prioritize this

This vulnerability scores 7.4 (HIGH) due to its network accessibility and cross-boundary impact, despite requiring authentication. The focus on data confidentiality and integrity in a widely-used CRM platform elevates operational risk. While not yet actively exploited, the relative ease of exploitation by any authenticated user and the potential for regulatory exposure warrant timely patching within 30–60 days rather than treating it as low-urgency. Organizations handling regulated data (PII, health, financial) should prioritize faster.

Risk score, explained

The CVSS:3.1 vector reflects a network-accessible vulnerability (AV:N) that can be exploited by low-privilege users (PR:L) without user interaction (UI:N) and affects confidentiality, integrity, and availability across trust boundaries (S:C/C:L/I:L/A:L). The 7.4 score balances the requirement for authentication (which reduces reach) against the broad impact potential and ease of execution. Organizations with restrictive authentication policies and logging oversight may experience lower practical risk; those with permissive access or poor monitoring face elevated danger.

Frequently asked questions