CVE-2026-120399 — Red Hat
HIGHCVE-2026-120399 is a high-severity (CVSS 7.5) CWE-1322 vulnerability. The records list no fixed version yet; check the vendor advisory below and apply the mitigations in the meantime.
A flaw was found in flightctl. A TLS handshake is performed synchronously in the HTTP server’s connection-context callback without a deadline. A network-reachable unauthenticated client…
Description
A flaw was found in flightctl. A TLS handshake is performed synchronously in the HTTP server’s connection-context callback without a deadline. A network-reachable unauthenticated client can stall the handshake and prevent the affected listener from accepting new connections.
Detection & mitigation playbook
VulnerabilityDetect
Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).
Remediation status
The records we use list no fixed release for CVE-2026-120399. Check the upstream advisory for a patched version, and apply the exposure-reduction steps below in the meantime.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Frequently Asked Questions
Is CVE-2026-120399 in your dependencies?
Find it across your dependency tree, including transitive dependencies.