CVE-2026-118383: Use-After-Free (CVSS 9)

Description

A use-after-free in the replication component of MongoDB Server can occur when a newly elected replica set primary completes catch-up. The condition can be caused by requests that do not require authentication, and may result in the server terminating unexpectedly or, under certain conditions, arbitrary code execution in the context of the server process. Replica set members are affected, including the shard and config server replica set members of sharded clusters; standalone mongod instances are not.

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CVSS v3.1 Score

9.0

CRITICAL

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H

EPSS — Exploit Prediction

0.0071

Probability of exploitation

0.54%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-416 Use After Free

References

Other References

https://jira.mongodb.org/browse/SERVER-138119 https://jira.mongodb.org/browse/SERVER-138175

Frequently Asked Questions

What is CVE-2026-118383? +

A use-after-free in the replication component of MongoDB Server can occur when a newly elected replica set primary completes catch-up. The condition can be caused by requests that do not require authentication, and may result in the server terminating unexpectedly or, under certain conditions, arbitrary code execution in the context of the server process. Replica set members are affected, including the shard and config server replica set members of sharded clusters; standalone mongod instances are not. It has a CVSS v3.1 base score of 9.0 (CRITICAL).

How severe is CVE-2026-118383? +

CVE-2026-118383 has a CVSS v3.1 score of 9.0 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately. The EPSS score is 0.0071, placing it in the 1th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-118383? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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