CVE-2026-56862: CWE-770: Allocation of Resources Without Limits or Throttling in Go standard library crypto/tls
CVE-2026-56862 is a resource allocation vulnerability in the Go standard library's crypto/tls package. The issue arises because handshake messages like KeyUpdate are always treated as state-advancing, even if the handshake is incomplete. This allows a malicious client to repeatedly send KeyUpdate messages, forcing the server to perform continuous key derivation operations without limits or throttling. This can lead to resource exhaustion on the server side.
AI Analysis
Technical Summary
The vulnerability in Go's crypto/tls package involves improper handling of handshake messages, specifically KeyUpdate messages, which are always considered state-advancing. This behavior enables a malicious client to send an unlimited number of KeyUpdate messages, causing the server to repeatedly perform computationally expensive key derivation operations indefinitely. This is classified under CWE-770, indicating allocation of resources without limits or throttling. Affected versions include =1.26.0-0, =1.27.0-0, <1.25.13, and >=1.26.0-0 <1.26.6. No CVSS score or official remediation level is provided, and no patch links are available at this time.
Potential Impact
The vulnerability can cause a denial of service condition by exhausting server resources through continuous key derivation operations triggered by malicious KeyUpdate messages. This may degrade server performance or cause service unavailability. There is no indication of code execution or data compromise from the provided information.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, consider implementing rate limiting or other controls at the application or network level to mitigate potential resource exhaustion from repeated KeyUpdate messages.
CVE-2026-56862: CWE-770: Allocation of Resources Without Limits or Throttling in Go standard library crypto/tls
Description
CVE-2026-56862 is a resource allocation vulnerability in the Go standard library's crypto/tls package. The issue arises because handshake messages like KeyUpdate are always treated as state-advancing, even if the handshake is incomplete. This allows a malicious client to repeatedly send KeyUpdate messages, forcing the server to perform continuous key derivation operations without limits or throttling. This can lead to resource exhaustion on the server side.
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in Go's crypto/tls package involves improper handling of handshake messages, specifically KeyUpdate messages, which are always considered state-advancing. This behavior enables a malicious client to send an unlimited number of KeyUpdate messages, causing the server to repeatedly perform computationally expensive key derivation operations indefinitely. This is classified under CWE-770, indicating allocation of resources without limits or throttling. Affected versions include =1.26.0-0, =1.27.0-0, <1.25.13, and >=1.26.0-0 <1.26.6. No CVSS score or official remediation level is provided, and no patch links are available at this time.
Potential Impact
The vulnerability can cause a denial of service condition by exhausting server resources through continuous key derivation operations triggered by malicious KeyUpdate messages. This may degrade server performance or cause service unavailability. There is no indication of code execution or data compromise from the provided information.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, consider implementing rate limiting or other controls at the application or network level to mitigate potential resource exhaustion from repeated KeyUpdate messages.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- Go
- Date Reserved
- 2026-06-23T15:10:49.353Z
- Cvss Version
- null
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a7e412ebf8831d539e05131
Added to database: 08/13/2026, 22:11:58 UTC
Last enriched: 08/13/2026, 22:27:33 UTC
Last updated: 08/14/2026, 00:29:20 UTC
Views: 5
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