Service interruption via TLS renegotiation CPU exhaustion
Published Dec 23, 2025 · Updated Dec 23, 2025
Resource exhaustion in Keycloak and Red Hat build of Keycloak affected releases allows remote attackers to interrupt service over TLS 1.2. TLS endpoints inherit a JDK default that accepts repeated client-initiated renegotiation handshakes, allowing unbounded cryptographic work to consume server CPU. Exploitation requires network access to a TLS-enabled endpoint but no authentication; the reported consequence is service unavailability, not data access or modification.
Summary
What happened
Resource exhaustion in Keycloak and Red Hat build of Keycloak affected releases allows remote attackers to interrupt service over TLS 1.2. TLS endpoints inherit a JDK default that accepts repeated client-initiated renegotiation handshakes, allowing unbounded cryptographic work to consume server CPU. Exploitation requires network access to a TLS-enabled endpoint but no authentication; the reported consequence is service unavailability, not data access or modification.
The record
- CVE
- CVE-2025-11419
- Published
- Dec 23, 2025
- Updated
- Dec 23, 2025
- Vendor
- 389 Directory Server
- Product
- Red Hat build of Keycloak
- Classifications
- CWE-400, CWE-770, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Dec 23, 2025CVE publishedPublication date reported by the CVE source.
- Dec 23, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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