A race condition vulnerability was discovered in how signals are handled by OpenSSH's server (sshd). If a remote attacker does not authenticate within a set time period, then sshd's SIGALRM handler is called asynchronously. However, this signal handler calls various functions that are not async-signal-safe, for example, syslog(). As a consequence of a successful attack, in the worst case scenario, an attacker may be able to perform a remote code execution (RCE) as an unprivileged user running the sshd server.
Conclusion & alert: CVE-2024-6409 is rated Moderate Risk (62.3/100): CVSS High severity, with high exploitation likelihood (EPSS 76.40%, 99th percentile). Core evidence: EPSS ranks this CVE among the most likely to be exploited in the near term. Mandatory action: High exploitation likelihood—assess exposure and prioritize remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-05-05 | 76.73% | 76.40% | -0.33% |
| 2 | 2026-04-22 | 76.40% | 76.73% | +0.33% |
| 3 | 2026-03-04 | — | 76.40% | — |
Full EPSS history (52 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 7.0 | 3.1 | HIGH |
|
2.2 | 4.7 | [email protected] |
| vendor | priority | summary | link |
|---|---|---|---|
debian
|
unimportant | CVE-2024-6409 unimportant priority: Debian including 1 source packages (openssh), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. | https://security-tracker.debian.org/tracker/CVE-2024-6409 |
redhat
|
medium | — | https://access.redhat.com/security/cve/CVE-2024-6409 |
suse
|
high | CVE-2024-6409 severity important: SUSE including 14 source package names (openssh, openssh-8.7p1-38.el9_4.4, …), 154 product×package rows across 34 product lines (SUSE Enterprise Storage 7.1, SUSE Liberty Linux 9, … (34 product lines)): Known Not Affected 148, Fixed 6. | https://www.suse.com/security/cve/CVE-2024-6409/ |
ubuntu
|
medium | CVE-2024-6409 medium priority: Ubuntu including 2 source packages (openssh, openssh-ssh1), 14 status rows across 8 suites (bionic, focal, jammy, mantic, noble, trusty, upstream, xenial): not-affected 12, ignored 1, needs-triage 1. | https://ubuntu.com/security/CVE-2024-6409 |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| No affected products in dataset. | |||