MongoDB Server OOM via deep nested expression evaluation
CVE-2026-1849 Published on February 10, 2026
Mongod can run out of stack memory when expressions create deeply nested documents
MongoDB Server may experience an out-of-memory failure while evaluating expressions that produce deeply nested documents. The issue arises in recursive functions because the server does not periodically check the depth of the expression.
Vulnerability Analysis
CVE-2026-1849 can be exploited with network access, and requires small amount of user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.
Weakness Type
What is a Stack Exhaustion Vulnerability?
The product does not properly control the amount of recursion which takes place, consuming excessive resources, such as allocated memory or the program stack.
CVE-2026-1849 has been classified to as a Stack Exhaustion vulnerability or weakness.
Products Associated with CVE-2026-1849
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Affected Versions
MongoDB Inc MongoDB Server:- Version 8.0 and below 8.0.18 is affected.
- Version 7.0 and below 7.0.29 is affected.
- Version 8.2 and below 8.2.2 is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.