CVE-2026-59846: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') in Red Hat Red Hat Enterprise Linux 10
A flaw was found in libssh. A malicious username expanded through %r in ProxyCommand handling can inject shell metacharacters, exposing environment variables and causing unintended shell behavior.
AI Analysis
Technical Summary
This vulnerability in libssh arises from improper handling of the username expansion through %r in ProxyCommand processing. A malicious username can inject shell metacharacters, causing unintended shell command execution and exposure of environment variables. The flaw is categorized under CWE-77 (OS Command Injection) and CWE-78 (Improper Neutralization of Special Elements). The CVSS v3.1 base score is 3.9 (low), reflecting local attack vector, low complexity, and low impact on confidentiality and integrity. Red Hat has issued updated libssh packages (version 0.12.1-4.hum1) for affected architectures to mitigate this issue.
Potential Impact
An attacker with local access and low privileges who can influence the username used in ProxyCommand may inject shell metacharacters, potentially exposing environment variables and causing unintended shell behavior. The impact is limited to low confidentiality and integrity loss with no availability impact. There are no known exploits in the wild. The vulnerability does not allow remote exploitation and requires user interaction.
Mitigation Recommendations
Red Hat has released updated libssh RPM packages (libssh-0.12.1-4.hum1 and related) that fix this vulnerability. Users of Red Hat Hardened Images should apply these updates promptly. Additionally, avoid executing connections with untrusted username inputs to reduce risk. Patch status is confirmed by Red Hat advisory RHSA-2026:42922. No other mitigations are specifically recommended by the vendor.
CVE-2026-59846: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') in Red Hat Red Hat Enterprise Linux 10
Description
A flaw was found in libssh. A malicious username expanded through %r in ProxyCommand handling can inject shell metacharacters, exposing environment variables and causing unintended shell behavior.
CVSS v3.1
Score 3.9low
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability in libssh arises from improper handling of the username expansion through %r in ProxyCommand processing. A malicious username can inject shell metacharacters, causing unintended shell command execution and exposure of environment variables. The flaw is categorized under CWE-77 (OS Command Injection) and CWE-78 (Improper Neutralization of Special Elements). The CVSS v3.1 base score is 3.9 (low), reflecting local attack vector, low complexity, and low impact on confidentiality and integrity. Red Hat has issued updated libssh packages (version 0.12.1-4.hum1) for affected architectures to mitigate this issue.
Potential Impact
An attacker with local access and low privileges who can influence the username used in ProxyCommand may inject shell metacharacters, potentially exposing environment variables and causing unintended shell behavior. The impact is limited to low confidentiality and integrity loss with no availability impact. There are no known exploits in the wild. The vulnerability does not allow remote exploitation and requires user interaction.
Mitigation Recommendations
Red Hat has released updated libssh RPM packages (libssh-0.12.1-4.hum1 and related) that fix this vulnerability. Users of Red Hat Hardened Images should apply these updates promptly. Additionally, avoid executing connections with untrusted username inputs to reduce risk. Patch status is confirmed by Red Hat advisory RHSA-2026:42922. No other mitigations are specifically recommended by the vendor.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- redhat
- Date Reserved
- 2026-07-07T15:40:24.561Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
- Vendor Advisory Urls
- [{"url":"https://access.redhat.com/security/cve/CVE-2026-59846","vendor":"Red Hat"}]
Threat ID: 6a5f703f2a4a8d59892bbe50
Added to database: 07/21/2026, 13:12:31 UTC
Last enriched: 08/13/2026, 13:19:18 UTC
Last updated: 09/01/2026, 19:22:46 UTC
Views: 59
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.