CVE-2026-48107: CWE-20: Improper Input Validation in Eugeny russh
Russh is a Rust SSH client & server library. From version 0.37.0 to before version 0.61.0, in the russh client keyboard-interactive authentication path, a malicious SSH server could send a USERAUTH_INFO_REQUEST with an attacker-controlled prompt count, and the client would use that raw count directly in Vec::with_capacity(...) before validating that enough prompt data was actually present in the packet. This issue has been patched in version 0.61.0.
AI Analysis
Technical Summary
Russh versions >=0.37.0 and <0.61.0 contain an input validation vulnerability (CWE-20) in the keyboard-interactive authentication mechanism. A malicious SSH server can send a USERAUTH_INFO_REQUEST message with an attacker-controlled prompt count. The russh client uses this raw count in Vec::with_capacity(...) without verifying that the packet includes enough prompt data, potentially leading to memory allocation issues or denial of service. The vulnerability is patched in version 0.61.0.
Potential Impact
The vulnerability does not impact confidentiality or integrity but can cause a denial of service (availability impact) by triggering improper memory allocation in the client. There are no known exploits in the wild. The CVSS v3.1 base score is 6.5 (medium severity), reflecting network attack vector, low attack complexity, no privileges required, user interaction required, unchanged scope, no confidentiality or integrity impact, and high availability impact.
Mitigation Recommendations
A fix is available in russh version 0.61.0. Users and developers should upgrade to version 0.61.0 or later to remediate this vulnerability. No other vendor advisory or temporary mitigations are provided.
CVE-2026-48107: CWE-20: Improper Input Validation in Eugeny russh
Description
Russh is a Rust SSH client & server library. From version 0.37.0 to before version 0.61.0, in the russh client keyboard-interactive authentication path, a malicious SSH server could send a USERAUTH_INFO_REQUEST with an attacker-controlled prompt count, and the client would use that raw count directly in Vec::with_capacity(...) before validating that enough prompt data was actually present in the packet. This issue has been patched in version 0.61.0.
CVSS v3.1
Score 6.5medium
Affected software
pkg:cargo/github/eugeny/russhRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
Russh versions >=0.37.0 and <0.61.0 contain an input validation vulnerability (CWE-20) in the keyboard-interactive authentication mechanism. A malicious SSH server can send a USERAUTH_INFO_REQUEST message with an attacker-controlled prompt count. The russh client uses this raw count in Vec::with_capacity(...) without verifying that the packet includes enough prompt data, potentially leading to memory allocation issues or denial of service. The vulnerability is patched in version 0.61.0.
Potential Impact
The vulnerability does not impact confidentiality or integrity but can cause a denial of service (availability impact) by triggering improper memory allocation in the client. There are no known exploits in the wild. The CVSS v3.1 base score is 6.5 (medium severity), reflecting network attack vector, low attack complexity, no privileges required, user interaction required, unchanged scope, no confidentiality or integrity impact, and high availability impact.
Mitigation Recommendations
A fix is available in russh version 0.61.0. Users and developers should upgrade to version 0.61.0 or later to remediate this vulnerability. No other vendor advisory or temporary mitigations are provided.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-05-20T18:46:58.287Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a29d0250e53e73883986cd5
Added to database: 6/10/2026, 8:59:17 PM
Last enriched: 6/10/2026, 9:15:11 PM
Last updated: 6/10/2026, 11:44:53 PM
Views: 8
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