The QUIC transport parameters extension handler in s2n-tls incorrectly uses s2n_alloc instead of s2n_realloc to store the peer's transport parameters. When a TLS 1.3 connection goes through a HelloRetryRequest, the handler is called twice on the same connection. On the second call, s2n_alloc zeroes the existing pointer before allocating new memory, causing the first allocation to be leaked. This can occur during normal QUIC traffic when a client offers a key share group the server does not prefer. An unauthenticated user can amplify the issue by deliberately forcing HelloRetryRequests, causing up to approximately 64 KB of unreachable memory per handshake. Over time, this can lead to increased memory consumption on long-running server processes. The unreachable memory is only reclaimed when the process is restarted. Only server-side QUIC-enabled deployments are affected. Non-QUIC TLS connections are not affected. We recommend you upgrade s2n-tls to version v1.7.6

The remote SUSE Linux SLES15 / SLES_SAP15 host has a package installed that is affected by multiple vulnerabilities as referenced in the SUSE-SU-2026:5101-1 advisory.

    Security issues fixed:

    - CVE-2026-16317: s2n-tls: man-in-the-middle attack can silently discard individual application data     records       (bsc#1272354).
    - CVE-2026-16318: s2n-tls: Denial of Service due to memory leak in QUIC transport parameters handler     (bsc#1272349).
    - CVE-2026-25541: bytes: integer overflow in 'BytesMut:reserve' can lead to undefined behavior and crashes       (bsc#1274202).

    Changes for aws-efs-utils:

    - Update to version 3.3.4

Tenable has extracted the preceding description block directly from the SUSE security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote openSUSE 16 host has packages installed that are affected by multiple vulnerabilities as referenced in the openSUSE-SU-2026:21501-1 advisory.

    Changes in s2n:

    - CVE-2026-16318: Denial of Service due to memory leak in QUIC       transport parameters handler (bsc#1272352)
    - CVE-2026-16317: man-in-the-middle attack can silently discard       individual application data records

Tenable has extracted the preceding description block directly from the SUSE security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

ID	Name	Product	Family	Type	Severity
376956	SUSE SLES15 Security Update : aws-efs-utils (SUSE-SU-2026:5101-1)	Nessus	SuSE Local Security Checks	Local	high
331558	openSUSE 16 Security Update : s2n (openSUSE-SU-2026:21501-1)	Nessus	SuSE Local Security Checks	Local	high

Detections

Analytics

CVE-2026-16318

medium

Tenable Plugins

high

high