CVE-2026-31828: 
JavaScript vulnerability analysis and mitigation

CVE-2026-31828 is an LDAP injection vulnerability in Parse Server's LDAP authentication adapter, allowing authenticated attackers to escalate privileges by bypassing group membership checks. It affects Parse Server (npm) versions prior to 8.6.26 and versions 9.0.0 through 9.5.2-alpha.12. The vulnerability was disclosed on March 10, 2026, with patches released the same day. It carries a CVSS v3.1 base score of 8.8 (High) and a CVSS v4.0 base score of 6.0 (Medium) (GitHub Advisory, Parse Server Advisory).

The root cause is CWE-90 (Improper Neutralization of Special Elements used in an LDAP Query). The authData.id field supplied by the user is interpolated directly into LDAP Distinguished Names (DN) and group search filter strings without escaping special characters as required by RFC 4514 and RFC 4515. An attacker with valid LDAP credentials can craft a malicious authData.id value containing LDAP special characters (e.g., *, (, ), \, NUL) to manipulate the bind DN structure and alter the logic of group membership filter queries. The vulnerability is only exploitable in Parse Server deployments that have the LDAP authentication adapter configured with group-based access control (Parse Server Advisory, GitHub Advisory).

Successful exploitation allows any authenticated LDAP user to escalate their privileges to that of a member of any restricted group within the Parse Server application, bypassing group-based access controls entirely. This can result in unauthorized access to protected resources, administrative functionality, or sensitive data gated behind group membership. The integrity impact is high within the vulnerable system, though confidentiality and availability of the system itself are not directly impacted by the injection (Parse Server Advisory, GitHub Advisory).

There is no public proof-of-concept exploit and no evidence of in-the-wild exploitation as of the time of disclosure (GitHub Advisory). The vulnerability is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog. The EPSS score is approximately 0.164% (37th percentile), indicating a low near-term probability of exploitation. Exploitation requires valid LDAP credentials and a Parse Server deployment configured with the LDAP adapter and group-based access control, limiting the attack surface (GitHub Advisory).

1. Identify target: Locate a Parse Server instance (version < 8.6.26 or 9.0.0–9.5.2-alpha.12) configured with the LDAP authentication adapter and group-based access control.
2. Obtain valid LDAP credentials: Acquire any valid LDAP user account credentials — these can be low-privilege user credentials, as no elevated access is required to initiate the attack.
3. Craft malicious authData.id: Construct an authentication request where the authData.id field contains LDAP special characters designed to manipulate the DN or group filter. For example, injecting characters such as *, )(, or null bytes to alter the LDAP filter logic (e.g., username)(|(cn=* to make the group filter always evaluate to true).
4. Submit authentication request: Send the crafted authentication payload to the Parse Server LDAP authentication endpoint, causing the server to construct a malformed LDAP query that bypasses group membership validation.
5. Achieve privilege escalation: The manipulated LDAP query causes the server to treat the attacker as a member of a restricted group, granting access to protected resources or administrative functionality (Parse Server Advisory, GitHub Advisory).

• Logs: Parse Server authentication logs showing login attempts with usernames containing LDAP special characters such as *, (, ), \, or null bytes in the authData.id field.
• Logs: LDAP server access logs showing unusual or malformed DN bind attempts or filter queries originating from the Parse Server host.
• Logs: Unexpected successful authentications by low-privilege LDAP users accessing resources or API endpoints restricted to privileged groups.
• Network: Authentication requests to Parse Server's LDAP adapter endpoint with anomalous or encoded characters in the user identifier field.

Upgrade Parse Server to version 8.6.26 (for the 8.x branch) or 9.5.2-alpha.13 (for the 9.x branch), both released on March 9, 2026. The fix escapes user input before interpolation into DN strings per RFC 4514 and LDAP filter strings per RFC 4515. There is no known configuration-based workaround; if immediate patching is not possible, consider disabling the LDAP authentication adapter or restricting network-level access to the Parse Server LDAP authentication endpoint until the patch can be applied (Parse Server Advisory, Release 8.6.26, Release 9.5.2-alpha.13).

The vulnerability was reported by security researcher 0xkakash1 and coordinated by Parse Server maintainer mtrezza, who published the advisory on March 10, 2026 (Parse Server Advisory). No significant broader media coverage or notable community commentary beyond the official advisory has been identified.