What is CVE-2025-40906?

CVE-2025-40906 is a critical-severity vulnerability in MongoDB Bson::xs, classified under Heap-based Buffer Overflow. CVSS score: 9.8/10. Published 2025-05-16.

How severe is CVE-2025-40906?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Is CVE-2025-40906 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Buffer overflow in MongoDB Bson::xs

CVE-2025-40906

BSON::XS versions 0.8.4 and earlier for Perl includes a bundled libbson 1.1.7, which has several vulnerabilities. Those include CVE-2017-14227, CVE-2018-16790, CVE-2023-0437, CVE-2024-6381, CVE-2024-6383, and CVE-2025-0755. BSON-XS was the official Perl XS implementation of MongoDB's BSON serialization, but this distribution has reached its end of life as of August 13, 2020 and is no longer supported.

Vulnerability class: Buffer Overflow

EPSS: 0.006 (46.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Mongodb Bson::xs — versions 0

Weakness classification (CWE)

Public proof-of-concept exploits

fkie-cad/nvd-json-data-feeds

References

9b29abf9-4ab0-4765-b253-1875cd9b441e (mailing-list)
9b29abf9-4ab0-4765-b253-1875cd9b441e (vendor-advisory)

Frequently asked questions

What is CVE-2025-40906?: CVE-2025-40906 is a critical-severity vulnerability in MongoDB Bson::xs, classified under Heap-based Buffer Overflow. CVSS score: 9.8/10. Published 2025-05-16.
How severe is CVE-2025-40906?: Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2025-40906 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.