Unsigned Integer Underflow Vulnerability in wolfSSH Affects Multiple Versions
CVE-2026-83742
5.3MEDIUM
What is CVE-2026-83742?
The vulnerability in wolfSSH arises from an unsigned integer underflow in the wstrncat() function, which negatively impacts stack memory handling. Specifically, authenticated remote attackers can exploit this flaw by submitting specially crafted SFTP paths. The improper calculation of buffer sizes can lead to an out-of-bounds write, potentially causing adjacent stack memory corruption and application crashes. Particular care should be taken by applications using public wolfSSH_RealPath() when handling output buffers that may be smaller than the input path. Patch updates related to this issue have been made in the wolfSSL repository.
Affected Version(s)
wolfSSH 1.4.11 <= 1.5.0
References
CVSS V4
Score:
5.3
Severity:
MEDIUM
Confidentiality:
None
Integrity:
Low
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None
Timeline
Vulnerability published
Vulnerability Reserved
Credit
Asif Nadaf <postasif@protonmail.com>, Independent Security Researcher