Memory Allocation with Excessive Size Value Affecting russh package, versions <0.60.1
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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- published29 Apr 2026
- disclosed24 Apr 2026
- creditcoreyleavitt
Introduced: 24 Apr 2026
NewCVE-2026-42189 (opens in a new tab)How to fix?
Upgrade russh to version 0.60.1 or higher.
Overview
Affected versions of this package are vulnerable to Memory Allocation with Excessive Size Value via the read_userauth_info_response function. An attacker can cause the server to allocate excessive memory and crash by sending a specially crafted USERAUTH_INFO_RESPONSE packet with a large count value before authentication. This is only exploitable if the server's keyboard-interactive authentication handler returns Auth::Partial, which is typical for multi-step authentication such as 2FA or TOTP.