CVE-2023-32186Network attack vector

Cluster join denial via TLS SAN stuffing

Published Sep 19, 2023 · Updated Sep 25, 2024

Resource exhaustion in SUSE RKE2 allows remote attackers to block new cluster connections through its TCP 9345 supervisor port. The dynamiclistener-backed supervisor adds every client-requested host name or IP address to its serving certificate because RKE2 omitted the address-filter callback. Repeated unauthenticated TLS handshakes can enlarge the SAN list beyond client limits, preventing server and agent nodes from joining or rejoining while existing servers keep operating.

CVSS severity7.5
High
EPSS probability0.69%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Resource exhaustion in SUSE RKE2 allows remote attackers to block new cluster connections through its TCP 9345 supervisor port. The dynamiclistener-backed supervisor adds every client-requested host name or IP address to its serving certificate because RKE2 omitted the address-filter callback. Repeated unauthenticated TLS handshakes can enlarge the SAN list beyond client limits, preventing server and agent nodes from joining or rejoining while existing servers keep operating.

The record

CVE
CVE-2023-32186
Published
Sep 19, 2023
Updated
Sep 25, 2024
Vendor
SUSE
Product
RKE2
Classifications
T1499.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 19, 2023CVE publishedPublication date reported by the CVE source.
  2. Sep 25, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1.24.0 <1.24.17\+/rke2r1
  2. Affected versionversion=1.24.0 <1.24.17+rke2r1
  3. Affected versionversion=1.25.0 <1.25.13\+/rke2r1
  4. Affected versionversion=1.26.0 <1.26.8\+/rke2r1
  5. Affected versionversion=1.27.0 <.27.5\+/rke2r1
  6. Affected versionversion=1.28.0 <1.28.1\+/rke2r1
  7. Affected versionversion=v1.25.0 <v1.25.13+rke2r1
  8. Affected versionversion=v1.26.0 <v1.26.8+rke2r1
  9. Affected versionversion=v1.27.0 <v1.27.5+rke2r1
  10. Affected versionversion=v1.28.0 <v1.28.1+rke2r1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

SUSE · RKE2version=1.24.0 <1.24.17\+/rke2r1; version=1.24.0 <1.24.17+rke2r1; version=1.25.0 <1.25.13\+/rke2r1; version=1.26.0 <1.26.8\+/rke2r1; version=1.27.0 <.27.5\+/rke2r1; version=1.28.0 <1.28.1\+/rke2r1; version=v1.25.0 <v1.25.13+rke2r1; version=v1.26.0 <v1.26.8+rke2r1; version=v1.27.0 <v1.27.5+rke2r1; version=v1.28.0 <v1.28.1+rke2r1

Published CVSS scores

7.5SUSECVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499.002Service Exhaustion Flood

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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