RKE2 supervisor port is vulnerable to unauthenticated remote denial-of-service (DoS) attack via TLS SAN stuffing attack
Published Sep 19, 2023 · Updated Oct 23, 2026 · Also known as GHSA-p45j-vfv5-wprq
Original summary
Normalized public record · Updated Oct 23, 2026
RKE2 supervisor port is vulnerable to unauthenticated remote denial-of-service (DoS) attack via TLS SAN stuffing attack
Publisher and source text is retained separately from QFinch interpretation.
QFinch assessment
An issue was found in RKE2 where an attacker with network access to RKE2 servers' supervisor port (TCP 9345) can force the TLS server to add entries to the certificate's Subject Alternative Name (SAN) list, through a stuffing attack, until the certificate grows so large that it exceeds the maximum size allowed by TLS client implementations. OpenSSL for example will raise an `excessive message size` error when this occurs. No authentication is necessary to perform this attack, only the ability to perform a TLS handshake against the supervisor port (TCP 9345).
Potential impact
An issue was found in RKE2 where an attacker with network access to RKE2 servers' supervisor port (TCP 9345) can force the TLS server to add entries to the certificate's Subject Alternative Name (SAN) list, through a stuffing attack, until the certificate grows so large that it exceeds the maximum size allowed by TLS client implementations. OpenSSL for example will raise an excessive message size error when this occurs. No authentication is necessary to perform this attack, only the ability to perform a TLS handshake against the supervisor port (TCP 9345). Affected servers will continue to operate, but clients (server or agent nodes) will fail to establish new connections when joining or rejoining the cluster, thus leading to a denial of service (DoS) attack.
Evidence: public source recordsAffected products
| Affected package, product or range | Fix status |
|---|---|
| Consult the referenced vendor advisory for affected versions. | Consult source advisory |
Matching a version is only one part of assessing exposure. QFinch has not assessed your environment on this public page.
Remediation
Apply the vendor-supported fixed release or mitigation, then verify the affected component is no longer reachable.
- Confirm the affected product and reachable code path exist in your environment.
- Apply the vendor-supported patch or mitigation from the primary advisory.
- Rescan the exact deployed revision and retain verification evidence.
Evidence coverage
- SSVC priority
- MEDIUM
- Confidence
- 10%
- Aliases
- GHSA-p45j-vfv5-wprq
Scores appear only when corresponding evidence exists. Missing data is never interpreted as zero risk.
Sources and record history
Record history
Published Sep 19, 2023 · Last refreshed Oct 23, 2026