CVE-2026-78662
Description
A flaw was found in golang.org/x/crypto/ssh. A malicious remote attacker could flood a channel's incoming requests before it is established, leading to a deadlock of the entire connection. This could result in a denial of service (DoS) for legitimate users.
Statement
A malicious SSH peer can flood a channel with crafted requests before the channel is fully established, causing the affected SSH connection to become unresponsive. This vulnerability does not affect confidentiality or integrity. Red Hat rates this issue as Moderate because the demonstrated availability impact is limited to the affected connection.
Mitigation
Red Hat is not aware of a practical mitigation that fully prevents this issue while maintaining affected SSH functionality. Where operationally possible, restrict SSH connectivity to trusted systems. Apply relevant Red Hat updates when they become available.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.3 | N/A | 7.5 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | High |
| Integrity Impact | None | N/A | None |
| Availability Impact | Low | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Resource Consumption (CPU); DoS: Resource Consumption (Other); DoS: Crash, Exit, or Restart
Each thread of execution will "hang" and prevent tasks from completing. In some cases, CPU consumption may occur if a lock check occurs in a tight loop.
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
