What it is
CVE-2025-14847 is an unauthenticated vulnerability affecting MongoDB Server. Mismatched length fields in Zlib compressed protocol headers may allow a read of uninitialized heap memory by an unauthenticated client....
Vulnerability report
MongoDB Server
MongoDB Server · affected before 8.2.3
Decision summary
Direct answers before the deeper technical record.
What it is
CVE-2025-14847 is an unauthenticated vulnerability affecting MongoDB Server. Mismatched length fields in Zlib compressed protocol headers may allow a read of uninitialized heap memory by an unauthenticated client....
Is it exploited?
Yes. Previdian tracks this CVE as a known exploited vulnerability. Confidence is confirmed. Listed in CISA KEV. Also confirmed by third-party sources.
Who is affected?
MongoDB Server affected before 8.2.3.
What should we do?
Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
Overview
Mismatched length fields in Zlib compressed protocol headers may allow a read of uninitialized heap memory by an unauthenticated client.
This issue affects all MongoDB Server v7.0 prior to 7.0.28 versions, MongoDB Server v8.0 versions prior to 8.0.17, MongoDB Server v8.2 versions prior to 8.2.3, MongoDB Server v6.0 versions prior to 6.0.27, MongoDB Server v5.0 versions prior to 5.0.32, MongoDB Server v4.4 versions prior to 4.4.30, MongoDB Server v4.2 versions greater than or equal to 4.2.0, MongoDB Server v4.0 versions greater than or equal to 4.0.0, and MongoDB Server v3.6 versions greater than or equal to 3.6.0.
Exploitation evidence
Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.
CVE
A trusted third party reported exploitation.
Nuclei Templates
Public scanner or PoC coverage increases practical exploitability.
Per-source evidence links for KEV attestations are available through the Previdian Pro API.
Learn about Pro API access| Source | Added |
|---|---|
| CVE First | 2026-06-01 10:47 UTC |
| CISA | 2026-06-02 14:04 UTC |
Detection
Make the evidence actionable in scanner, SOC, and edge-control workflows.
Request targets and User-Agents available in Pro. Callback host details available in Enterprise.
Nuclei template detected 01 Jun 2026.
View Nuclei template (opens in new tab)No Previdian virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.
Learn about virtual patches →Scanner and exploit-framework references linked to this CVE.
| Scanner | Reference | Detected |
|---|---|---|
| Nuclei | https://github.com/projectdiscovery/nuclei-templates/blob/main/javascript/cves/2025/CVE-2025-14847.yaml | 01 Jun 2026 |
Risk and context
CVSS v4.0
Potential damage if exploited. Separate from whether attackers are using it.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
EPSS
83.2%
Estimated chance of exploitation in the next 30 days. Previdian's warning comes from evidence, not this score.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
These PoCs are unverified and could contain malware. Use at your own risk.
nuclei · Created Unknown
nuclei · Created Unknown
Timeline
14:21 UTC
Public proof-of-concept code published
14:04 UTC
Listed in the CISA Known Exploited Vulnerabilities catalog
15:34 UTC
Scanner coverage available
10:47 UTC
High-confidence, third-party attested exploitation
11:00 UTC
Vulnerability disclosed publicly
18:56 UTC
Identifier reserved by the CNA
Pro API
Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.
GET /api/v2/pro/kevs/CVE-2025-14847
Free JSON includes basic KEV fields{
"cve_id": "CVE-2025-14847",
"confidence": "Confirmed",
"cvss_score": 8.7,
"cvss_estimated": false,
"epss_score": 0.83218,
"exploit_status": {
"exploited_in_the_wild": true,
"active_exploitation_observed": false
},
"sensor_telemetry": { "attempts": 0, "sensors": 0 }
}