CVE-2026-59843: Loop with Unreachable Exit Condition ('Infinite Loop') in Red Hat Red Hat Enterprise Linux 10
A flaw was found in libssh. A remote authenticated peer can advertise a zero maximum packet size in SSH_MSG_CHANNEL_OPEN, causing later channel writes to loop indefinitely and consume CPU, leading to denial of service.
AI Analysis
Technical Summary
This vulnerability in libssh allows a remote authenticated peer to advertise a zero maximum packet size during the SSH_MSG_CHANNEL_OPEN message. This causes subsequent channel writes to enter an infinite loop, consuming CPU resources indefinitely and causing a denial of service. The issue is classified under CWE-835 (Loop with Unreachable Exit Condition) and affects Red Hat Hardened Images. Red Hat has published an advisory and released updated libssh RPM packages (version 0.12.1-4.hum1) to address this issue.
Potential Impact
The vulnerability leads to denial of service through resource exhaustion (CPU consumption) when a malicious remote authenticated user exploits the infinite loop condition. There is no impact on confidentiality or integrity, but availability is significantly affected.
Mitigation Recommendations
Red Hat has released updated libssh packages (libssh-0.12.1-4.hum1 and related RPMs) that fix this vulnerability. Users should apply these updates as soon as possible. No workaround or alternative mitigation is available. Refer to the Red Hat advisory at https://access.redhat.com/security/cve/CVE-2026-59843 for update instructions.
CVE-2026-59843: Loop with Unreachable Exit Condition ('Infinite Loop') in Red Hat Red Hat Enterprise Linux 10
Description
A flaw was found in libssh. A remote authenticated peer can advertise a zero maximum packet size in SSH_MSG_CHANNEL_OPEN, causing later channel writes to loop indefinitely and consume CPU, leading to denial of service.
CVSS v3.1
Score 6.5medium
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability in libssh allows a remote authenticated peer to advertise a zero maximum packet size during the SSH_MSG_CHANNEL_OPEN message. This causes subsequent channel writes to enter an infinite loop, consuming CPU resources indefinitely and causing a denial of service. The issue is classified under CWE-835 (Loop with Unreachable Exit Condition) and affects Red Hat Hardened Images. Red Hat has published an advisory and released updated libssh RPM packages (version 0.12.1-4.hum1) to address this issue.
Potential Impact
The vulnerability leads to denial of service through resource exhaustion (CPU consumption) when a malicious remote authenticated user exploits the infinite loop condition. There is no impact on confidentiality or integrity, but availability is significantly affected.
Mitigation Recommendations
Red Hat has released updated libssh packages (libssh-0.12.1-4.hum1 and related RPMs) that fix this vulnerability. Users should apply these updates as soon as possible. No workaround or alternative mitigation is available. Refer to the Red Hat advisory at https://access.redhat.com/security/cve/CVE-2026-59843 for update instructions.
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-2026-59843","vendor":"Red Hat"}]
Threat ID: 6a5f5b1f2a4a8d59890f9723
Added to database: 07/21/2026, 11:42:23 UTC
Last enriched: 08/13/2026, 13:19:00 UTC
Last updated: 08/31/2026, 22:52:12 UTC
Views: 66
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.