MongoDB libmongocrypt up to 1.20.2 input validation

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
Current Exploit Price (≈)
Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.
CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
5.2$0-$5k0.64

Summaryinfo

A vulnerability, which was classified as critical, has been found in MongoDB libmongocrypt up to 1.20.2. This affects an unknown function. Performing a manipulation results in input validation. This vulnerability is reported as CVE-2026-81523. The attack is possible to be carried out remotely. No exploit exists.

Detailsinfo

A vulnerability, which was classified as critical, was found in MongoDB libmongocrypt up to 1.20.2. This affects an unknown functionality. The manipulation with an unknown input leads to a input validation vulnerability. CWE is classifying the issue as CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

A missing input-validation issue in MongoDB libmongocrypt's automatic-encryption context setup allows a caller-supplied database identifier to be accepted without sanitization. The resulting impact is limited to incorrect schema selection, which may lead to limited disclosure or modification of information handled by the application.

It is possible to read the advisory at github.com. This vulnerability is uniquely identified as CVE-2026-81523 since 08/27/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. The technical details are unknown and an exploit is not publicly available.

Upgrading to version 1.20.3 eliminates this vulnerability.

Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 5.4
VulDB Meta Temp Score: 5.2

VulDB Base Score: 6.3
VulDB Temp Score: 6.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 4.4
CNA Vector (mongodb): 🔒

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock

VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Input validation
CWE: CWE-20
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

0-DayUnlockUnlockUnlockUnlock
TodayUnlockUnlockUnlockUnlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: libmongocrypt 1.20.3

Timelineinfo

08/27/2026 Advisory disclosed
08/27/2026 +0 days CVE reserved
08/27/2026 +0 days VulDB entry created
08/27/2026 +0 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-81523 (🔒)
GCVE (CVE): GCVE-0-2026-81523
GCVE (VulDB): GCVE-100-396327

Entryinfo

Created: 08/27/2026 22:32
Changes: 08/27/2026 22:32 (76)
Complete: 🔍
Cache ID: 216::103

Be aware that VulDB is the high quality source for vulnerability data.

Discussion

No comments yet. Languages: en.

Please log in to comment.

◂ PreviousOverviewNext ▸

Do you need the next level of professionalism?

Upgrade your account now!