Buffer overflow in Cesanta Mongoose
CVE-2026-5245
A vulnerability was found in Cesanta Mongoose up to 7.20. This impacts the function handle_mdns_record of the file mongoose.c of the component mDNS Record Handler. Performing a manipulation of the argument buf results in stack-based buffer overflow. Remote exploitation of the attack is possible. A high degree of complexity is needed for the attack. The exploitability is said to be difficult. The exploit has been made public and could be used. Upgrading to version 7.21 will fix this issue. The patch is named 0d882f1b43ff2308b7486a56a9d60cd6dba8a3f1. You should 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.
Vulnerability class: Buffer Overflow
EPSS: 0.007 (50.0th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.6 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L.
Affected products
- Cesanta Mongoose — versions 7.0, 7.1, 7.2
Weakness classification (CWE)
References
- cna@vuldb.com (technical-description, VDB Entry, Third Party Advisory, vdb-entry)
- cna@vuldb.com (signature, Permissions Required, permissions-required, VDB Entry)
- cna@vuldb.com (VDB Entry, Third Party Advisory, third-party-advisory)
- cna@vuldb.com (Patch, patch)
- cna@vuldb.com (Product, Release Notes, patch)
- cna@vuldb.com (Product, product)
Frequently asked questions
- What is CVE-2026-5245?
- CVE-2026-5245 is a medium-severity vulnerability in Cesanta Mongoose, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 5.6/10. Published 2026-04-02.
- How severe is CVE-2026-5245?
- Medium severity. CVSS v3 base score is 5.6 out of 10.