CVE-2026-81518
BI Connector Optional Client Certificate Verification Allows Unauthenticated Connections
Description
When mongosqld is configured with a client certificate authority file, the listener requests a client certificate during the TLS handshake but does not require one, so a client that presents no certificate is still accepted. In deployments that rely on client certificates as the sole means of identifying users, a remote party with network access to the listener can therefore establish a session and read the MongoDB data exposed through the connector.
INFO
Published Date :
Aug. 28, 2026, 10:16 p.m.
Last Modified :
Aug. 28, 2026, 10:16 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-81518
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | a39b4221-9bd0-4244-95fc-f3e2e07f1deb | ||||
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 3.1 | HIGH | MITRE-CVE | ||||
| CVSS 4.0 | HIGH | a39b4221-9bd0-4244-95fc-f3e2e07f1deb | ||||
| CVSS 4.0 | HIGH | [email protected] |
Solution
- Configure mongosqld to require client certificates.
- Ensure CA file is correctly specified.
- Restart mongosqld service.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-81518.
| URL | Resource |
|---|---|
| https://www.mongodb.com/docs/bi-connector/current/release-notes/ |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-81518 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-81518
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-81518 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-81518 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Aug. 28, 2026
Action Type Old Value New Value Added Description When mongosqld is configured with a client certificate authority file, the listener requests a client certificate during the TLS handshake but does not require one, so a client that presents no certificate is still accepted. In deployments that rely on client certificates as the sole means of identifying users, a remote party with network access to the listener can therefore establish a session and read the MongoDB data exposed through the connector. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/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:X/R:X/V:X/RE:X/U:X Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N Added CWE CWE-295 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/81xxx/CVE-2026-81518.json">CVE-2026-81518</a> Added Reference https://www.mongodb.com/docs/bi-connector/current/release-notes/