Known exploited · MongoDB
CVE-2025-14847: MongoDB and MongoDB Server Improper Handling of Length Parameter Inconsistency Vulnerability
What it is
MongoDB Server contains an improper handling of length parameter inconsistency vulnerability in Zlib compressed protocol headers. This vulnerability may allow a read of uninitialized heap memory by an unauthenticated client.
- Vendor
- MongoDB
- Product
- MongoDB and MongoDB Server
- Added to KEV
- December 29, 2025
- CISA due date
- January 19, 2026
- Ransomware use
- Unknown
What CISA requires
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Forensic triage
No
What to do now
- Find every instance of MongoDB and MongoDB Server you run, including the forgotten ones, and check its version against the vendor advisory.
- Apply the vendor's fix or mitigation, before January 19, 2026 if you are bound by CISA's deadline, sooner if it faces the internet.
- Assume it was tried against you already: look for signs of exploitation from the date it was added, not from the day you patched.
References
H2 Security
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Start freeSource: CISA Known Exploited Vulnerabilities Catalog (public domain), catalog version 2026.10.01.