CVE-2026-5244

High

Description

A vulnerability has been found in Cesanta Mongoose up to 7.20. This affects the function mg_tls_recv_cert of the file mongoose.c of the component TLS 1.3 Handler. Such manipulation of the argument pubkey leads to heap-based buffer overflow. The attack may be launched remotely. The exploit has been disclosed to the public and may be used. Upgrading to version 7.21 mitigates this issue. The name of the patch is 0d882f1b43ff2308b7486a56a9d60cd6dba8a3f1. It is advisable to upgrade the affected component. The vendor was contacted early, responded in a very professional manner and quickly released a fixed version of the affected product.

SeverityHigh
CVSS7.3
Exploit probability—
ProductCesanta Mongoose
PublishedApr 2, 2026
First seenApr 2, 2026

How to fix

Affected products

ProductAffected versionsFixed in
cesanta mongoose7.0 ≤ v < 7.217.21

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