Goal Reached Thanks to every supporter — we hit 100%!

Goal: 1000 CNY · Raised: 1336 CNY

100%
Buy Us a Coffee

CVE-2026-81528— NoSQL injection via array replacement bypassing update shape validation in driver write path

Quick assessment

Affected
MongoDB C# Driver
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

MongoDB C驱动中用于文档替换（document-replacement）的代码路径，省略了等效写入路径所应用的元素名称/结构验证。因此，作为替换值传入的数据未经过查询语言特殊元素的中和处理，直接被转发到服务器。如果应用程序将不可信、松散类型的输入作为替换值传递，该输入就会被数据库解释为更新逻辑，而非普通数据，并以应用程序自身的数据库凭据执行。使用强类型文档映射的应用程序不受此问题影响。

CVSS 5.4 · Medium
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2026-81528

Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗

Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.

Vulnerability Title
NoSQL injection via array replacement bypassing update shape validation in driver write path
Source: CVE Program / CVE List V5
Vulnerability Description
A MongoDB C# driver document-replacement code path omits the element-name/shape validation that the equivalent write paths apply, so a value supplied as a replacement is forwarded to the server without neutralization of query-language special elements. An application that passes untrusted, loosely-typed input as a replacement value therefore allows that input to be interpreted by the database as update logic rather than as data, executing under the application's own database credentials. Applications using strongly-typed document mappings are not affected.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
Source: CVE Program / CVE List V5
Vulnerability Type
数据查询逻辑中特殊元素的不当中和
Source: CVE Program / CVE List V5

Affected Products

Vendor Product Affected Versions CPE Subscribe
MongoDB C# Driver 2.9.0 ~ 3.11.1 -

II. Public POCs for CVE-2026-81528

# POC Description Source Link Shenlong Link
AI-Generated POC Premium

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2026-81528

请登录查看更多情报信息。

Other References for CVE-2026-81528 (1)

Same Patch Batch · MongoDB · 2026-08-27 · 12 CVEs total

CVE-2026-81522 8.1 HIGH Cross-tenant database retargeting via dot/NUL injection in namespace strings in the C++ Dr
CVE-2026-81525 8.1 HIGH Cross-tenant database retargeting via dot/NUL injection in namespace strings in the PHP Dr
CVE-2026-81529 7.1 HIGH Connection-option injection via unescaped settings in the canonical MongoDB URL builder
CVE-2026-81521 6.5 MEDIUM Cross-database write retargeting via unvalidated dotted database name in Client.BulkWrite
CVE-2026-81527 6.5 MEDIUM NoSQL injection via unquoted constant GroupBy keys in LINQ pipeline translation
CVE-2026-81526 6.5 MEDIUM Cross-database write redirection via unvalidated dotted database name in bulk write namesp
CVE-2026-75159 5.9 MEDIUM MongoDB BI Connector Improper Memory Handling During Failed Kerberos Authentication May Ca
CVE-2026-81530 5.6 MEDIUM KMS master key exposure via unredacted credential serialization in driver settings string
CVE-2026-81524 5.4 MEDIUM Cross-tenant database retargeting via dot/NUL injection in namespace strings in the C Driv
CVE-2026-75573 4.4 MEDIUM MongoDB Connector for BI mongodrdl Logs TLS Private-Key Password When Duplicate Options Ar
CVE-2026-81523 4.4 MEDIUM Cross-tenant database retargeting via dot/NUL injection in namespace strings in libmongocr

IV. Related Vulnerabilities

Same product: C# Driver
Same vendor: MongoDB
Same weakness: CWE-943

V. Comments for CVE-2026-81528

No comments yet

Leave a comment