NVD / CVE Program· CNA mongodb

CVE-2026-8336: Post-authentication use-after-free error in $_internalJsEmit and mapreduce commands

Noroxi assessment

Priority: Monitor (action score 30/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 0.25% (FIRST EPSS).
Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. No user action is required. Special conditions such as timing or configuration are required.
According to the record, no fixed version is available yet.

Low priority for now. Update when a fix is released; follow the vendor's advisory.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

After invoking $_internalJsEmit, which is not intended to be directly accessible, or mapreduce command’s map function in a certain way, an authenticated user can subsequently crash mongod when the server-side JavaScript engine (through $where, $function, mapreduce reduce stage, etc.) is used also in a specific way, resulting in a post-authentication denial-of-service. This issue impacts MongoDB Server v8.2 versions prior to 8.2.9 and v8.3 versions prior to 8.3.2.

HighCVSS 7.7 · v4.0—No exploit No fix recorded

Memory safety

Published: May 13, 2026
Updated: Oct 26, 2026
EPSS: 0.2% · 17th percentile
CWE: CWE-416

Report tools

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Action score

Monitor

Low priority for now.

CVSS: 30 / 40 · 7.7 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.2%

CISA SSVC decision

Exploitation: none
Automatable: no
Technical impact: total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: —
CNA · mongodb: 7.7; NVD has not scored this yet; the score shown is the CNA’s.

CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/AU:N/R:A/V:D/RE:M/U:Red

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

Not in KEV: no record of exploitation in the wild
No public exploit code on record
No fixed version yet

If any of these changes, we'll tell you in the daily email digest.

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
mongodb	mongodb	cpe:2.3:a:mongodb:mongodb

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

mongodb mongodb8.2.0 and later · before 8.2.9
mongodb mongodb8.3.0 and later · before 8.3.2

Versions reported by the vendor

Affected version ranges reported by the assigning authority (mongodb). Independent of NVD's CPE analysis and usually ahead of it.

MongoDB, Inc. MongoDB Server
- 8.2 and later · before 8.2.9affected
- 8.3 and later · before 8.3.2affected

Same product

mongodb: all records

Other highest-scoring records for the same primary product.

CVE-2025-14847Zlib compressed protocol header length confusion may allow memory readKEV
89Now
CVE-2013-1892MongoDB before 2.0.9 and 2.2.x before 2.2.4 does not properly validate requests to the nativeHelper function in SpiderMonkey, which allows r
40Plan
CVE-2025-3085MongoDB Server running on Linux may allow unexpected connections where intermediate certificates are revoked
39Monitor

Published before and after this one in the same product

← EarlierCVE-2026-8201May 13, 2026 · Use-After-Free in MongoDB FLE Query Analysis When Processing Positional Projections on Encrypted Fields
24Monitor
← EarlierCVE-2026-8202May 13, 2026 · Post-authentication CPU utilization DoS via $trim/$ltrim/$rtrim operators
21Monitor
Later →CVE-2026-8843May 18, 2026 · Calling createIndex with certain index types can crash mongod
28Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

No fix version is recorded for this entry. Check the references for vendor advisories.

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

CVE-2025-6706321 days apartRunning certain aggregation operations with the SBE engine may lead to unexpected behavior on MongoDB Server
35Monitor
CVE-2026-414857 days apartExpressionContext use-after-free in classic engine $lookup and $graphLookup aggregation operators
34Monitor
CVE-2026-1869290 days apartUse-After-Free in MongoDB Timeseries Bucket Handling Leads to Denial of Service and Potential Remote Code Execution
30Monitor
CVE-2026-1870690 days apartUse-After-Free in MongoDB $graphLookup Aggregation Stage Leads to Denial of Service and Potential Remote Code Execution
30Monitor
CVE-2026-1307170 days apartServer-Side JavaScript Aggregation Expression Memory Safety Issue Leading to Process Termination
28Monitor
CVE-2026-1871190 days apartUse-After-Free in MongoDB Query Execution Engine Leads to Denial of Service and Potential Memory Disclosure
28Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

MongoDBHackerOne · paid

The product’s vendor appears in a public program. Matched by name; verify the scope text in the program.

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
A low-privileged account is enough.
No user action is required.
Special conditions such as timing or configuration are required.

If successful

Confidentiality
Integrity
Availability

Attack vector: Network
Attack complexity: High
Privileges required: Low
User interaction: None
Scope: X

Weakness class (CWE)

CWE-416 · Use After Free

CVSS vector

CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:N/R:A/V:D/RE:M/U:Red

nvd-secondary

Root cause

After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.

The bug in code

The whole CWE-416 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1free(dev->buf);
2/* ... another thread is still running ... */
3process(dev->buf);

Fixed

1lock(&dev->lock);
2free(dev->buf);
3dev->buf = NULL;
4unlock(&dev->lock);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.

References

jira.mongodb.org/browse/SERVER-121610

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records