CVE-2026-11703: wolfSSL improper authentication in session-ID resumption

CVE-2026-11703 · Severity: info · CVSS 6 · Published 2026-06-25

wolfSSL is a security library used to encrypt communications for various applications and devices. A flaw was found where the library failed to properly verify certain connection details (SNI and ALPN) when resuming a previously established secure session. This could allow an attacker to reuse an authenticated session in a different context where they should not have access, potentially bypassing security policies that differ between virtual hosts.

Technologies: Wolfssl. Vendors: Wolfssl.

Quick answers

Is CVE-2026-11703 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-11703 being exploited in the wild.
How severe is CVE-2026-11703?
Informational severity, with a CVSS score of 6, published 25 June 2026.
Which products and versions are affected?
Wolfssl 3.15.0 through 5.9.1.
Is there a fix for CVE-2026-11703?
A patch was published on 2026-06-05: Fix merged into wolfSSL master branch Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-11703 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-11703?
Check whether you run Wolfssl 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.

Technical details

A vulnerability exists in wolfSSL's TLS 1.2 and 1.3 session resumption logic. Specifically, stateful (session-ID) resumption previously skipped the binding checks for Server Name Indication (SNI) and Application-Layer Protocol Negotiation (ALPN) that were already implemented for ticket-based resumption. An attacker with a valid cached session could resume that session under a different SNI or ALPN than originally negotiated. In environments where client-authentication policies vary across virtual hosts, this allows the cached peer-authentication state to be applied to a context for which it was not established. The fix ensures resumption verifies SNI/ALPN bindings for all paths and falls back to a full handshake on mismatch.

Affected products

  • wolfSSL wolfSSL 3.15.0 through 5.9.1

Timeline

  • 2026-05-14: disclosed: Initial pull request submitted to wolfSSL GitHub
  • 2026-06-05: patched: Fix merged into wolfSSL master branch
  • 2026-06-25: advisory: CVE-2026-11703 published

References

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