Threats Tagged 'cve-2026-16317'

Bulletin ID: 2026-062-AWS Scope: AWS Content Type: Important (requires attention) Publication Date: 07/21/2026 13:15 PM PDT Description: s2n-tls is an open source C99 implementation of the TLS/SSL protocol. We have identified two distinct issues: - CVE-2026-16317: Silent Drop of TLS 1.3 Encrypted Records in s2n-tls 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 drop 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. All TLS 1.3 connections are affected. Both TLS clients and servers are affected. TLS 1.2 and QUIC connections are not affected. - CVE-2026-16318: QUIC Transport Parameters Memory Leak During HelloRetryRequest in s2n-tls Incorrect use of s2n_alloc instead of s2n_realloc in the QUIC transport parameters extension handler in s2n-tls causes one memory allocation to be leaked each time a QUIC-enabled TLS 1.3 connection goes through a HelloRetryRequest. This can occur during normal handshakes when a client offers a key share group the server does not prefer, and can lead to increased memory consumption on long-running server processes. Only QUIC-enabled deployments are affected. Impacted versions: <= v1.7.5 Please refer to the article below for the most up-to-date and complete information related to this AWS Security Bulletin.

This security update for s2n addresses two vulnerabilities: CVE-2026-16318, a denial of service caused by a memory leak in the QUIC transport parameters handler, and CVE-2026-16317, a man-in-the-middle attack that can silently discard individual application data records. Both issues affect the s2n component used by SUSE. No specific affected versions or patch details are provided in the available data.