CVE-2026-96297 — MongoDB Server may disclose process memory via a crafted `$_internalApplyOplogUpdate` aggregation pipeline
Use of freed memory in the aggregation feature of MongoDB Server can cause the server to read data from a memory area after it has been released. When an internal aggregation stage is combined with a batch size of 0, the server may read from memory that is no longer in use. Because that memory can be reused for other data before it is read, query results returned to the client may contain unrelated data from the server process. Depending on the state of memory at the time, the server process may also terminate unexpectedly. The behavior can occur when an authenticated user with read privileges runs an aggregate command that combines these two settings.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.2% (30-day exploitation probability)+2
- Technical severity (medium)+3
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Mongodb MongoDB Server).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Mongodb | MongoDB Server | ≥ 8.3.0 and < 8.3.13≥ 8.0 and < 8.0.34≥ 7.0 and < 7.0.45≥ 9.0 and < 9.0.2 | Vulnerable | CVE Program (cve.org) e CISA ADP |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 6.0 | CVSS 4.0 | Medium | — | — | cna@mongodb.com via NIST National Vulnerability Database |
| 6.0 | CVSS 4.0 | Medium | — | — | mongodb via CVE Program (cve.org) e CISA ADP |
| 6.5 | CVSS 3.1 | Medium | 2.8 | 3.6 | cna@mongodb.com via NIST National Vulnerability Database |
| 6.5 | CVSS 3.1 | Medium | — | — | GitHub, Inc. via GitHub Security Advisories |
| 6.5 | CVSS 3.1 | Medium | — | — | mongodb via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N (score shown at the top: cna@mongodb.com) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
EPSS over time FIRST
Oct 14, 2026 → Oct 15, 2026 · 2 reading(s) · max 0.22%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
- Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.
Timeline
What happened to this CVE, newest first.
- 2026
- Source status changed · Received → Awaiting Analysis
- Affected products added · mongodb/mongodb server
- SSVC assessment updated
- Record published
- CVSS changed · 6.5
- Source status changed · → Received
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× References added · Oct 15, 2026 – Oct 15, 2026
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
3 on the record
Elsewhere on this site
Related CVEs (same products)
- Medium CVE-2026-96299 Missing Authorization Check on Internal Aggregation Stage in MongoDB Server mongos Leads to Denial of Service 2d
- Medium CVE-2026-104005 Incorrect authorization in MongoDB Server router for bulk writes to system namespaces 2d
- Medium CVE-2026-103965 Fixed values in MongoDB Server $bucket stage may be misread as field references 2d
- Medium CVE-2026-104004 Collection validators using collation-accepting expressions can crash MongoDB Server on insert 2d
- High CVE-2026-89099 Race Condition in MongoDB Server Document Value Layer Leads to Memory Corruption Sep 11, 2026
- Medium CVE-2026-82073 Improper Validation in MongoDB Server Aggregation Framework Allows Authorization Bypass and Unauthorized Collection Access with Atlas Search Sep 8, 2026
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No fixed version, patch or mitigation documented.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-96297 is "MongoDB Server may disclose process memory via a crafted `$_internalApplyOplogUpdate` aggregation pipeline", rated Medium. It affects MongoDB Server (Mongodb); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 6.5 describes technical severity. EPSS 0.22% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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