CVE-2026-55723
Authenticated CRD/annotation injection allows arbitrary NGINX configuration directives.
Is CVE-2026-55723 being exploited?
Not confirmed. CVE-2026-55723 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.51% probability of exploitation in the next 30 days.
How severe is CVE-2026-55723?
CVE-2026-55723 is rated High with a CVSS score of 8.7. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-55723?
Yes. A fix has been recorded for CVE-2026-55723. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-55723 affect?
CVE-2026-55723 affects NGINX Ingress Controller, Kubernetes Ingress, Ingress CRDs/annotations, Kubernetes API (write access required). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-55723?
Restrict RBAC for CRD/Ingress write; audit Ingress annotations; apply vendor patch when released.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Authenticated users with write access to Ingress CRDs/annotations can inject arbitrary NGINX directives, create/delete files, or disable services (control-plane compromise).
Immediate action required
- affected>= 5.0.0 and < 5.5.2
- affected>= 2026-lts-r1 and < 2026-lts-r3
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.