Out-of-bounds write in Mongoose - CVE-2021-26530
Published: June 23, 2025
Vulnerability identifier: #VU111817
CSH Severity: High
CVSS v4: 9.2 [CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2021-26530
CWE-ID: CWE-787
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to compromise vulnerable system.
The vulnerability exists due to a boundary error within the mg_tls_init() function. A remote attacker can initiate multiple connection requests to exhaust available memory pool, trigger an out-of-bounds write and execute arbitrary code on the target system.
Affected software
Mongoose
How to mitigate CVE-2021-26530
Install updates from vendor's website.
Mongoose - update to 7.1