Is CVE-2020-25756 actively exploited?

No active exploitation of CVE-2020-25756 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2020-25756 be exploited remotely?

Yes. CVE-2020-25756 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2020-25756?

CVE-2020-25756 has a CVSS score of 9.8 (CRITICAL).

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CRITICAL

CVE-2020-25756

CWE-120Published: September 18, 2020· Updated: Jun 17, 2026

9.8

CVSS v3.1

Official Description

A buffer overflow vulnerability exists in the mg_get_http_header function in Cesanta Mongoose 6.18 due to a lack of bounds checking. A crafted HTTP header can exploit this bug. NOTE: a committer has stated "this will not happen in practice.

NVD Source

Technical Analysis

CVE-2020-25756 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.