CVE-2026-118581 (CVSS 6.5)

Description

A BSON encoding component of the MongoDB Java Driver does not verify that an externally supplied raw document's self-declared length agrees with the extent of the byte range it is given before that range is copied into an outgoing database command. An application that wraps untrusted raw bytes in such a document and uses it as part of a command can therefore emit a structurally inconsistent message, causing the database to interpret attacker-supplied trailing content as additional fields of the surrounding command. No authentication to the driver or database is required beyond the ability to influence those bytes through the victim application, and no user interaction is needed. The result is unintended modification of the command actually executed, which can alter the data read or written under the application's credentials.

Is your site exposed to CVE-2026-118581?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

6.5

MEDIUM

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

EPSS — Exploit Prediction

0.0019

Probability of exploitation

0.09%

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-943 CWE-943

References

Other References

https://github.com/mongodb/mongo-java-driver/releases/tag/r5.14.0

Frequently Asked Questions

What is CVE-2026-118581? +

A BSON encoding component of the MongoDB Java Driver does not verify that an externally supplied raw document's self-declared length agrees with the extent of the byte range it is given before that range is copied into an outgoing database command. An application that wraps untrusted raw bytes in such a document and uses it as part of a command can therefore emit a structurally inconsistent message, causing the database to interpret attacker-supplied trailing content as additional fields of the surrounding command. No authentication to the driver or database is required beyond the ability to influence those bytes through the victim application, and no user interaction is needed. The result is unintended modification of the command actually executed, which can alter the data read or written under the application's credentials. It has a CVSS v3.1 base score of 6.5 (MEDIUM).

How severe is CVE-2026-118581? +

CVE-2026-118581 has a CVSS v3.1 score of 6.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0019, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-118581? +

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.

Related Vulnerabilities

CVE-2026-78691

Improper Neutralization of Special Elements in Data Query Logic vulnerability in ash-project ash_sql allows a user who supplies a search …

CVE-2026-57193

Asterisk is an open source private branch exchange and telephony toolkit. Prior to Asterisk 20.20.1, 21.12.3, 22.10.1, 23.4.1 and Certified …

CVE-2026-105799

LangChain is a framework for building LLM-powered applications. Prior to 1.1.1, @langchain/redis does not escape attacker-controlled values in structured RediSearch …

CVE-2026-42156

Flowsint is an open-source OSINT graph exploration tool designed for cybersecurity investigation, transparency, and verification. Prior to 1.2.3, a remote …

CVE-2026-47181

PenguinMod-BackendApi is the backend api for penguinmod. Prior to version 1.0.0, a NoSQL injection vulnerability in the password reset endpoint …

CVE-2026-73976

djehuty is a research data repository system developed by 4TU.ResearchData. Prior to version 26.3.2, An unauthenticated attacker can inject SPARQL …

CVE-2026-118581