Out-of-bounds Read in Cesanta Mongoose

CVE-2026-11404

Cesanta Mongoose before 7.22 contains an out-of-bounds read in the built-in TLS server function mg_tls_server_recv_hello(), which uses an attacker-controlled session_id_len byte from a TLS ClientHello as a buffer index without validating i…

Vulnerability class: Buffer Overflow

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-11404?
CVE-2026-11404 is a high-severity vulnerability in Cesanta Mongoose, classified under Out-of-bounds Read. CVSS score: 7.5/10. Published 2026-07-09.
How severe is CVE-2026-11404?
High severity. CVSS v3 base score is 7.5 out of 10.