Security readout for executives and security teams
Plain-English summary
A remote, unauthenticated attacker can crash an affected per-connection daemon process during GSSAPI authentication, but only when packet-level logging is enabled. The evidence supports connection-level service disruption; it does not establish a system-wide outage.
Executive priority
Prioritize exposed systems meeting both runtime conditions: GSSAPI authentication and packet-level logging. Patch during the next accelerated maintenance window, sooner for important externally reachable services. Emergency organization-wide action is not supported by the supplied evidence because exploitation has specific configuration prerequisites and no active exploitation is reported.
Technical view
Zero-length input passed to libssh's ssh_get_hexa() can cause denial of service during GSSAPI authentication when logging is SSH_LOG_PACKET (3) or higher. CVSS 3.0 is 6.5, with network access, high attack complexity, no privileges, no user interaction, and high availability impact.
Likely exposure
Exposure is concentrated in network-reachable services using affected libssh packages, GSSAPI authentication, and logging verbosity level 3 or higher. Listed affected platforms include RHEL 8–10, certain Red Hat Hardened Images, and OpenShift Container Platform 4 components. Listed libssh2 packages are unaffected.
Exploitation context
The attack is remote and requires no authentication, but depends on GSSAPI processing and unusually verbose packet logging, supporting the high-complexity rating. The bundle reports no CISA KEV listing and provides no evidence of active exploitation.
Researcher notes
The reported outcome is a self-denial of service affecting the per-connection daemon process. Do not infer host-wide compromise or confidentiality loss. The affected matrix distinguishes libssh from unaffected libssh2 packages. Exact fixed distribution package versions are absent, so validation should use the cited vendor advisories rather than upstream version assumptions.
Mitigation direction
- Apply the applicable Red Hat security advisory updates after confirming package and platform applicability.
- Consult libssh or Red Hat guidance for precise fixed versions; the bundle does not provide them.
- Reduce logging below SSH_LOG_PACKET level 3 where operationally acceptable until updates are applied.
- Restrict network access to affected services where verbose logging cannot be reduced promptly.
Validation and detection
- Inventory installed libssh and libssh-main packages across listed Red Hat and OpenShift platforms.
- Confirm whether exposed services use GSSAPI authentication paths.
- Check runtime logging configuration for SSH_LOG_PACKET level 3 or higher.
- Verify installed package versions against the applicable Red Hat advisory.
- Confirm updated services remain available and expected authentication still functions.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-124: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupContainer behavior lookup
The affected technology mentions containers, so container-specific ATT&CK technique review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-0966 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 6.5 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H2.24.2redhatVulnerability scoring details
Base CVSS 3.0 score
6.5MediumVector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- Source timelineredhat
Reported to Red Hat.
- Source timelineredhat
Made public.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- RHSA-2026:18160CVE reference, redhat · vendor-advisory, x_refsource_REDHAT
- RHSA-2026:18683CVE reference, redhat · vendor-advisory, x_refsource_REDHAT
- RHSA-2026:7067CVE reference, redhat · vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/security/cve/CVE-2026-0966CVE reference, redhat · vdb-entry, x_refsource_REDHAT
- RHBZ#2433121CVE reference, redhat · issue-tracking, x_refsource_REDHAT
- https://www.libssh.org/2026/02/10/libssh-0-12-0-and-0-11-4-security-releases/CVE reference, redhat
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Buffer Underwrite ('Buffer Underflow')
Buffer Underwrite ('Buffer Underflow') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.