Vulnerability Intelligence Report
Limit handshake messages we are willing to accept post-handshake in crypto/tls
CVE-2026-56862
Handshake messages, such as KeyUpdate, are always considered as state-advancing, regardless of whether a handshake has been completed or not. As a result, a malicious client can keep sending KeyUpdate messages to force the server to keep performing key derivation operations indefinitely.
No Active Exploit Signals
CVSS Base Score
7.5
HIGH
Exploitability:3.9
Impact Score:3.6
EPSS Probability:0.18%
Executive Threat Verdict
Evaluating...
Evaluating Threat Landscape...
Assessing known weaponization, exploitation telemetry, and federal advisories.
Attack Surface
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Authentication
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Weaponization
—
SSVC Action
—
Weaknesses (CWE)
CWE-770 ↗CWE-770: Allocation of Resources Without Limits or Throttling
Affected Products & Versions
| Vendor | Product | Affected Versions |
|---|---|---|
| Go standard library | crypto/tls | 0 < 1.25.13 (affected), 1.26.0-0 < 1.26.6 (affected), 1.27.0-0 < 1.27.0-rc.3 (affected) |
References & Technical Advisories
No reference links found.
Threat Intelligence Signals
EPSS Score
0.185%
GitHub Advisory
Identity & Timeline
| Status | PUBLISHED |
| Assigning Authority | Go Project · Vendor · USA |
| Reserved | 2026-06-23T15:10:49 |
| Published | 2026-08-13T21:58:53 |
| Last Updated | 2026-08-14T15:29:41 |
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