cvedb.io
CVE-2026-16317
MEDIUM · CVSS 6.5
EPSS exploitation probability: 0%
Published 2026-07-21T21:16:49.060 · Last modified 2026-07-21T21:16:49.060

Summary

Missing validation of the outer content_type byte on TLS 1.3 encrypted records in s2n-tls allows an active man-in-the-middle to silently discard individual application data records without either endpoint detecting the modification. RFC 8446 Section 5.2 requires that the outer content_type of all encrypted TLS 1.3 records must be application_data (0x17). The s2n-tls AEAD implementation hardcodes this value in the additional authenticated data rather than using the actual wire byte, so the outer content_type is not covered by the authentication tag. This enables selective suppression of application data. In HTTP pipelining scenarios, dropping a TLS record containing an HTTP request can cause request/response desynchronization, where subsequent responses are delivered to the wrong reques

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.