CVE-2026-5170 — Users could trigger a crash of mongod primaries during promotion to sharded
A user with access to the cluster with a limited set of privilege actions can trigger a crash of a mongod process during the limited and unpredictable window when the cluster is being promoted from a replica set to a sharded cluster. This may cause a denial of service by taking down the primary of the replica set. This issue affects MongoDB Server v8.2 versions prior to 8.2.2, MongoDB Server v8.0 versions between 8.0.18, MongoDB Server v7.0 versions between 7.0.31.
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 0.3% (30-day exploitation probability)+4
- 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.
- Documented patch — jira.mongodb.org (NIST National Vulnerability Database)
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, Mongodb MongoDB Server).
- Apply the fixed version or the patch documented under Remediation.
- Search available logs for exploit probes, errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Mongodb | Mongodb | ≥ 7.0.0 and < 7.0.31≥ 8.0.0 and < 8.0.18≥ 8.2.0 and < 8.2.2 | Vulnerable | NIST National Vulnerability Database |
| Mongodb | MongoDB Server | ≥ 8.2 and < 8.2.2≥ 8.0 and < 8.0.18≥ 7.0 and < 7.0.31 | 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 |
| 5.3 | CVSS 3.1 | Medium | 1.6 | 3.6 | cna@mongodb.com via NIST National Vulnerability Database |
| 5.3 | CVSS 3.1 | Medium | 1.6 | 3.6 | nvd@nist.gov via NIST National Vulnerability Database |
| 5.3 | CVSS 3.1 | Medium | — | — | mongodb via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H (score shown at the top: nvd@nist.gov) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
EPSS over time FIRST
Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.34%
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).
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · mongodb/mongodb server
- SSVC assessment updated
- Record published
- Fix documented
- CVSS changed · 5.3
- Source status changed · → Analyzed
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
1 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-2026-96297 MongoDB Server may disclose process memory via a crafted `$_internalApplyOplogUpdate` aggregation pipeline 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
- Medium CVE-2026-9737 During query planning when reading the sort pattern in raw BSONObj form, in some places… Jul 22, 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 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-2026-5170 is "Users could trigger a crash of mongod primaries during promotion to sharded", rated Medium. It affects Mongodb (Mongodb); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 5.3 describes technical severity. EPSS 0.34% 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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