Red Hat Enterprise Linux 10: Loop with Unreachable Exit Condition
CVE-2026-59849 is a high-severity loop with unreachable exit condition vulnerability in Red Hat Enterprise Linux 10 from Red Hat, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. There is no confirmed exploitation so far. EPSS estimates a 0.44% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Libssh to 0.11.5 or a later version.
- Read the advisory on access.redhat.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Red Hat | Red Hat Enterprise Linux 10 | Not specified in the record | Not stated |
| Red Hat | Red Hat Hardened Images | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 8 | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 9 | Not specified in the record | Not stated |
| Libssh | Libssh | 0.11.0 up to, but not including, 0.11.5; 0.12.0 | 0.11.5 |
| Red Hat | Hardened Images | Not specified in the record | Not stated |
| Red Hat | Enterprise Linux | 10.0; 10.2 | Not stated |
| Red Hat | Enterprise Linux For Els | 10.2 | Not stated |
| Red Hat | Enterprise Linux For EUS | 10.2 | Not stated |
| Red Hat | Enterprise Linux For IBM Z Systems | 10.0; 10.2 | Not stated |
| Red Hat | Enterprise Linux For IBM Z Systems Els | 10.2 | Not stated |
| Red Hat | Enterprise Linux For IBM Z Systems EUS | 10.2 | Not stated |
| Red Hat | Enterprise Linux For Power Little Endian | 10.0; 10.2 | Not stated |
| Red Hat | Enterprise Linux For Power Little Endian Els | 10.2 | Not stated |
| Red Hat | Enterprise Linux For Power Little Endian EUS | 10.2 | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 3.1 | Low | CNA (redhat.com) |
| CVSS 3.1 | 7.5 | High | NVD |
Official description
A flaw was found in libssh. Logic errors in automatic certificate-based public key authentication can cause libssh clients to loop indefinitely when configured certificates are missing or repeatedly rejected by a server, leading to denial of service.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Loop with Unreachable Exit Condition
The product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop.
More Loop with Unreachable Exit Condition vulnerabilities (CWE-835)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Other references
- access.redhat.com/errata/RHSA-2026:42922Issue Tracking
Other vulnerabilities in Red Hat Enterprise Linux 10
- 8.8 High severity
- 7.5 High severity
- 7.5 High severity
- 7.9 High severity
- 7.3 High severity
- 7.5 High severity
Recent Loop with Unreachable Exit Condition vulnerabilities
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 8.1 High severity
- 7.5 High severity
- 7.5 High severity
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