MongoDB Mongoid up to 9.1.0 In-Memory Query Evaluation denial of service

Summaryinfo

A vulnerability identified as problematic has been detected in MongoDB Mongoid up to 9.1.0. The impacted element is an unknown function of the component In-Memory Query Evaluation. This manipulation causes denial of service. The identification of this vulnerability is CVE-2026-93761. It is possible to initiate the attack remotely. There is no exploit available.

Detailsinfo

A vulnerability was found in MongoDB Mongoid up to 9.1.0. It has been declared as problematic. Affected by this vulnerability is some unknown functionality of the component In-Memory Query Evaluation. The manipulation with an unknown input leads to a denial of service vulnerability. The CWE definition for the vulnerability is CWE-404. The product does not release or incorrectly releases a resource before it is made available for re-use. As an impact it is known to affect availability. The summary by CVE is:

An inefficient regular expression complexity issue in the in-memory query evaluation component of the Mongoid library may allow an unauthenticated party to cause excessive processing within an embedding application process. Applications that place user-supplied text into a pattern-matching query condition on an embedded association may become unresponsive.

The advisory is shared at jira.mongodb.org. This vulnerability is known as CVE-2026-93761 since 09/18/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Neither technical details nor an exploit are publicly available. MITRE ATT&CK project uses the attack technique T1499 for this issue.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

• Database Software

Vendor

• MongoDB

Name

• Mongoid

Version

• 7.2.0
• 7.2.1
• 7.2.2
• 7.2.3
• 7.2.4
• 7.2.5
• 7.2.6
• 7.3.0
• 7.3.1
• 7.3.2
• 7.3.3
• 7.3.4
• 7.3.5
• 7.4.0
• 7.4.1
• 7.4.2
• 7.4.3
• 7.5.0
• 7.5.1
• 7.5.2
• 7.5.3
• 7.5.4
• 7.6.0
• 7.6.1
• 8.0.0
• 8.0.1
• 8.0.2
• 8.0.3
• 8.0.4
• 8.0.5
• 8.0.6
• 8.0.7
• 8.0.8
• 8.0.9
• 8.0.10
• 8.0.11
• 8.0.12
• 8.1.0
• 8.1.1
• 8.1.2
• 8.1.3
• 8.1.4
• 8.1.5
• 8.1.6
• 8.1.7
• 8.1.8
• 8.1.9
• 8.1.10
• 8.1.11
• 8.1.12
• 9.0
• 9.0.0
• 9.0.1
• 9.0.2
• 9.0.3
• 9.0.4
• 9.0.5
• 9.0.6
• 9.0.7
• 9.0.8
• 9.0.9
• 9.0.10
• 9.0.11
• 9.1.0

License

• open-source

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Discussion