CVE-2025-63235

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-08-07 · updated 2026-09-29
Weakness: CWE-400

Description

In sol commit 373d848 (2024-12-12), the broker does not fully release resources when handling malformed or duplicate CONNECT packets. When clients send invalid CONNECT packets - either due to repeated attempts or failed authentication - the server may silently drop the connection or send a CONNACK but fail to close the session or deallocate internal resources. This behavior allows an attacker to create numerous half-open connections that consume memory and file descriptors indefinitely, potentially triggering the Linux OOM killer and causing a denial of service.

References

https://github.com/codepr/sol/issues/12
https://github.com/peter-pe/sol-vulnerabilities/blob/main/CVE-2025-63235.md
https://github.com/codepr/sol/issues/12
https://github.com/peter-pe/sol-vulnerabilities/blob/main/CVE-2025-63235.md

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