What’s Vulnerable › Vulnerabilities
CVE-2026-106435: Application denial of service via out-of-bounds read in BSON Regex decoding in MongoDB Python Driver
- Severity: medium (CVSS 4.7 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.1% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-10-08 · updated 2026-10-15
- Weakness: CWE-125
Description
The MongoDB Python Driver's binary accelerator can read outside a buffer when an application decodes malformed BSON containing a truncated regular-expression element without a trailing NUL byte. An actor who can supply BSON to the documented decode or decode_all API can cause the application process to terminate when the C extension is loaded. The driver's normal database wire-protocol path does not reach this code.
Affected products
- MongoDB Python Driver: before 4.18.3 — fixed in 4.18.3
How to fix
Upgrade to a fixed version: MongoDB Python Driver 4.18.3. Check the vendor advisory for mitigations.
References
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