OPENSUSE-SU-2026:21474-1 Security update for s2n

This update for s2n fixes the following issues: Changes in s2n: - CVE-2026-16318: Denial of Service due to memory leak in QUIC transport parameters handler bsc1272352 - CVE-2026-16317: man-in-the-middle attack can silently discard individual application data records...

SUSE CVE-2026-16318

The QUIC transport parameters extension handler in s2n-tls incorrectly uses s2nalloc instead of s2nrealloc 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, s2nalloc zeroes...

CVE-2026-55991 Remote DNS-over-QUIC (DoQ) flow-control assertion failure in libngtcp2

In NLnet Labs Unbound 1.22.0 up to and including 1.25.1, a remote unauthenticated client can trigger a libngtcp2 assertion if compiled with assertions on and terminate the entire Unbound process using a single DNS-over-QUIC DoQ connection and one normal DNS query. This is caused by an erroneous...

Missing Release of Memory after Effective Lifetime

Overview Affected versions of this package are vulnerable to Missing Release of Memory after Effective Lifetime in the QUIC transport parameters extension handler during the processing of HelloRetryRequest messages. An attacker can cause increased memory consumption by repeatedly triggering...

CVE-2026-16318

The QUIC transport parameters extension handler in s2n-tls incorrectly uses s2nalloc instead of s2nrealloc 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, s2nalloc zeroes...

CVE-2026-16318

The CVE-2026-16318 issue affects server-side QUIC deployments using s2n-tls, where the QUIC transport parameters extension handler uses s2n_alloc instead of s2n_realloc. During TLS 1.3 HelloRetryRequest, the handler runs twice on the same connection; on the second run it zeroes the existing point...

CVE-2026-16318 QUIC Transport Parameters Memory Leak During HelloRetryRequest in s2n-tls

The QUIC transport parameters extension handler in s2n-tls incorrectly uses s2nalloc instead of s2nrealloc 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, s2nalloc zeroes...

CVE-2026-16318 QUIC Transport Parameters Memory Leak During HelloRetryRequest in s2n-tls

The QUIC transport parameters extension handler in s2n-tls incorrectly uses s2nalloc instead of s2nrealloc 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, s2nalloc zeroes...

PT-2026-62072

Name of the Vulnerable Software and Affected Versions s2n-tls versions prior to v1.7.6 Description The QUIC transport parameters extension handler incorrectly uses s2n alloc instead of s2n realloc to store peer transport parameters. In TLS 1.3 connections involving a HelloRetryRequest, the handle...

ngtcp2: ngtcp2: Denial of service via stack buffer overflow during QUIC handshake

A flaw was found in ngtcp2, a C implementation of the IETF QUIC Quick UDP Internet Connections protocol. A remote attacker can exploit a stack buffer overflow vulnerability by sending specially crafted, large transport parameters during the QUIC handshake. This occurs when the qlog callback is...

ngtcp2: ngtcp2: Denial of service via stack buffer overflow during QUIC handshake

A flaw was found in ngtcp2, a C implementation of the IETF QUIC Quick UDP Internet Connections protocol. A remote attacker can exploit a stack buffer overflow vulnerability by sending specially crafted, large transport parameters during the QUIC handshake. This occurs when the qlog callback is...

USN-8300-1 ngtcp2 vulnerability

Zou Dikai discovered that ngtcp2 serialized peer transport parameters into a fixed 1024-byte stack buffer without bounds checking. When qlog was enabled, a remote attacker could possibly use this issue to execute arbitrary code...

Important: ngtcp2

Issue Overview: ngtcp2 is a C implementation of the IETF QUIC protocol. In versions prior to 1.22.1, ngtcp2qlogparameterssettransportparams serializes peer transport parameters into a fixed 1024-byte stack buffer without bounds checking. When qlog is enabled, a remote peer can send sufficiently...

ngtcp2: ngtcp2: Denial of service via stack buffer overflow during QUIC handshake

A flaw was found in ngtcp2, a C implementation of the IETF QUIC Quick UDP Internet Connections protocol. A remote attacker can exploit a stack buffer overflow vulnerability by sending specially crafted, large transport parameters during the QUIC handshake. This occurs when the qlog callback is...

SUSE CVE-2026-40170

ngtcp2 is a C implementation of the IETF QUIC protocol. In versions prior to 1.22.1, ngtcp2qlogparameterssettransportparams serializes peer transport parameters into a fixed 1024-byte stack buffer without bounds checking. When qlog is enabled, a remote peer can send sufficiently large transport...

CVE-2026-40170

A flaw was found in ngtcp2, a C implementation of the IETF QUIC Quick UDP Internet Connections protocol. A remote attacker can exploit a stack buffer overflow vulnerability by sending specially crafted, large transport parameters during the QUIC handshake. This occurs when the qlog callback is...

CVE-2026-40170

ngtcp2 is a C implementation of the IETF QUIC protocol. In versions prior to 1.22.1, ngtcp2qlogparameterssettransportparams serializes peer transport parameters into a fixed 1024-byte stack buffer without bounds checking. When qlog is enabled, a remote peer can send sufficiently large transport...

ALPINE-CVE-2026-40170

ngtcp2 is a C implementation of the IETF QUIC protocol. In versions prior to 1.22.1, ngtcp2qlogparameterssettransportparams serializes peer transport parameters into a fixed 1024-byte stack buffer without bounds checking. When qlog is enabled, a remote peer can send sufficiently large transport...

DEBIAN-CVE-2026-40170

ngtcp2 is a C implementation of the IETF QUIC protocol. In versions prior to 1.22.1, ngtcp2qlogparameterssettransportparams serializes peer transport parameters into a fixed 1024-byte stack buffer without bounds checking. When qlog is enabled, a remote peer can send sufficiently large transport...

CVE-2026-40170 ngtcp2 has a qlog transport parameter serialization stack buffer overflow

ngtcp2 is a C implementation of the IETF QUIC protocol. In versions prior to 1.22.1, ngtcp2qlogparameterssettransportparams serializes peer transport parameters into a fixed 1024-byte stack buffer without bounds checking. When qlog is enabled, a remote peer can send sufficiently large transport...