CVE-2026-11703
Missing SNI/ALPN binding on stateful (session-ID) resumption, which previously skipped the binding check performed for ticket-based resumption. A cached session could be resumed under a different SNI/ALPN than originally negotiated and, where client-authentication policy differs across virtual hosts, carry the cached peer-authentication state into a context it was not established for. Resumption now verifies the SNI/ALPN binding for all paths and declines (falling back to a full handshake) on mismatch.
CSIRTS triage
- What
- Missing SNI/ALPN binding on stateful TLS session resumption.
- Who is affected
- Users of affected TLS implementations.
- Urgency
- Remediation is urgent due to the high severity of the vulnerability.
- Action
- Implement necessary configurations to ensure SNI/ALPN binding.
AI-assisted analysis generated from the source advisory — verify against the original.
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Exploitation outlook
- Low exploitation risk0.21% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 11% of all EPSS-scored CVEs.
Advisory coverage (2)
External references
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