CVE-2026-56862: GO-2026-6090 - Limit handshake messages we are willing to accept post-handshake in crypto/tls

CVE-2026-56862 · Severity: info · Published 2026-08-13

Limit handshake messages we are willing to accept post-handshake in crypto/tls

Technologies: stdlib (Go). Vendors: Go.

Quick answers

Is CVE-2026-56862 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-56862 being exploited in the wild.
How severe is CVE-2026-56862?
Informational severity, published 13 August 2026.
Which products and versions are affected?
stdlib (Go) SEMVER:introduced=0,fixed=1.25.13,introduced=1.26.0-0,fixed=1.26.6,introduced=1.27.0-0,fixed=1.27.0-rc.3.
Is there a fix for CVE-2026-56862?
Yes. stdlib (Go): upgrade to 1.27.0-rc.3 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
Am I affected by CVE-2026-56862?
Check whether you run stdlib (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • stdlib (Go): upgrade to 1.27.0-rc.3 or later
    go get stdlib@v1.27.0-rc.3

Affected products

  • stdlib (Go) SEMVER:introduced=0,fixed=1.25.13,introduced=1.26.0-0,fixed=1.26.6,introduced=1.27.0-0,fixed=1.27.0-rc.3

Identifiers

  • CVE-2026-56862
  • GO-2026-6090

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