Linux Distros Unpatched Vulnerability : CVE-2026-75804

medium Nessus Plugin ID 351159

Synopsis

The Linux/Unix host has one or more packages installed with a vulnerability that the vendor indicates will not be patched.

Description

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

- Issue summary: OpenSSL QUIC stack does not enforce connection level flow control for streams. Remote peers may send more bytes as long as they fit within the stream flow control limits. Impact summary: A malicious remote peer may exploit the lack of connection flow control for streams to make the QUIC stack receive ~100MB of memory instead of 768 KiB (default flow control window size). CWE: CWE-770: Allocation of Resources Without Limits or Throttling Description: The local QUIC stack advertises two flow control limits to its remote peer: stream flow control limit and connection flow control limit. The remote peer must follow both limits when transmitting stream data. Whenever the local QUIC stack receives a stream frame, it validates that the size of the received stream frame stays within flow control limits. If either limit is exceeded (stream level or connection level), then the QUIC stack must close the connection with a flow control error. The vulnerable OpenSSL QUIC stack enforces the stream-level but not the connection- level limit. To exploit the issue, three conditions must be met: - the remote peer opens several streams - each stream must stay within the stream-level flow control limit - there must be no zero-offset byte sent on any of the streams (to prevent the vulnerable QUIC stack from consuming data). By meeting the conditions above, the remote peer may make the local stack allocate 2 x MAX_STREAMS x (stream flow control limit) bytes of memory. MAX_STREAMS defaults to 100, and the limit applies to both bidirectional and unidirectional streams, making it 200 in total. The default flow control window for a stream is 512kB. The remote peer may force the vulnerable QUIC stack to allocate 100MB of heap per connection. FIPS impact: no The FIPS module is not affected as the QUIC implementation is outside of the OpenSSL FIPS module boundary.
(CVE-2026-75804)

Note that Nessus relies on the presence of the package as reported by the vendor.

Solution

There is no known solution at this time.

Plugin Details

Severity: Medium

ID: 351159

File Name: unpatched_CVE_2026_75804.nasl

Version: 1.2

Type: Local

Agent: unix

Family: Misc.

Published: 9/29/2026

Updated: 9/30/2026

Supported Sensors: Frictionless Assessment AWS, Frictionless Assessment Azure, Frictionless Assessment Agent, Nessus Agent, Agentless Assessment, Tenable Cloud Security, Tenable Self-Hosted Container Security, Nessus

Risk Information

VPR

Risk Factor: Low

Score: 1.2

Percentile: 0.01

CVSS v2

Risk Factor: Medium

Base Score: 5

Temporal Score: 4.3

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P

CVSS Score Source: CVE-2026-75804

CVSS v3

Risk Factor: Medium

Base Score: 5.3

Temporal Score: 4.9

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Temporal Vector: CVSS:3.0/E:U/RL:U/RC:C

Vulnerability Information

CPE: cpe:/o:canonical:ubuntu_linux:22.04:-:lts, cpe:/o:canonical:ubuntu_linux:26.04:-:lts, cpe:/o:centos:centos:7, cpe:/o:centos:centos:8, cpe:/o:debian:debian_linux:13.0, cpe:/o:debian:debian_linux:14.0, cpe:/o:redhat:enterprise_linux:10, cpe:/o:redhat:enterprise_linux:6, cpe:/o:redhat:enterprise_linux:7, cpe:/o:redhat:enterprise_linux:8, cpe:/o:redhat:enterprise_linux:9, p-cpe:/a:canonical:ubuntu_linux:edk2-hwe, p-cpe:/a:canonical:ubuntu_linux:edk2, p-cpe:/a:canonical:ubuntu_linux:nodejs, p-cpe:/a:centos:centos:aavmf, p-cpe:/a:centos:centos:compat-openssl10, p-cpe:/a:centos:centos:compat-openssl11, p-cpe:/a:centos:centos:edk2-aarch64, p-cpe:/a:centos:centos:edk2-ovmf, p-cpe:/a:centos:centos:edk2-tools-doc, p-cpe:/a:centos:centos:edk2-tools, p-cpe:/a:centos:centos:edk2, p-cpe:/a:centos:centos:mingw-openssl, p-cpe:/a:centos:centos:mingw32-openssl, p-cpe:/a:centos:centos:mingw64-openssl, p-cpe:/a:centos:centos:mokutil, p-cpe:/a:centos:centos:openssl-devel, p-cpe:/a:centos:centos:openssl-libs, p-cpe:/a:centos:centos:openssl-perl, p-cpe:/a:centos:centos:openssl-static, p-cpe:/a:centos:centos:openssl, p-cpe:/a:centos:centos:ovmf, p-cpe:/a:centos:centos:shim-aa64, p-cpe:/a:centos:centos:shim-ia32, p-cpe:/a:centos:centos:shim-signed, p-cpe:/a:centos:centos:shim-unsigned-aarch64, p-cpe:/a:centos:centos:shim-unsigned-x64, p-cpe:/a:centos:centos:shim-x64, p-cpe:/a:centos:centos:shim, p-cpe:/a:debian:debian_linux:openssl, p-cpe:/a:redhat:enterprise_linux:aavmf, p-cpe:/a:redhat:enterprise_linux:compat-openssl10, p-cpe:/a:redhat:enterprise_linux:compat-openssl11, p-cpe:/a:redhat:enterprise_linux:edk2-aarch64, p-cpe:/a:redhat:enterprise_linux:edk2-ovmf, p-cpe:/a:redhat:enterprise_linux:edk2-tools-doc, p-cpe:/a:redhat:enterprise_linux:edk2-tools, p-cpe:/a:redhat:enterprise_linux:edk2, p-cpe:/a:redhat:enterprise_linux:mingw-openssl, p-cpe:/a:redhat:enterprise_linux:mingw32-openssl, p-cpe:/a:redhat:enterprise_linux:mingw64-openssl, p-cpe:/a:redhat:enterprise_linux:mokutil, p-cpe:/a:redhat:enterprise_linux:openssl-devel, p-cpe:/a:redhat:enterprise_linux:openssl-libs, p-cpe:/a:redhat:enterprise_linux:openssl-perl, p-cpe:/a:redhat:enterprise_linux:openssl-static, p-cpe:/a:redhat:enterprise_linux:openssl, p-cpe:/a:redhat:enterprise_linux:ovmf, p-cpe:/a:redhat:enterprise_linux:shim-aa64, p-cpe:/a:redhat:enterprise_linux:shim-ia32, p-cpe:/a:redhat:enterprise_linux:shim-signed, p-cpe:/a:redhat:enterprise_linux:shim-unsigned-aarch64, p-cpe:/a:redhat:enterprise_linux:shim-unsigned-x64, p-cpe:/a:redhat:enterprise_linux:shim-x64, p-cpe:/a:redhat:enterprise_linux:shim

Required KB Items: Host/local_checks_enabled, Host/cpu, global_settings/vendor_unpatched, Host/OS/identifier

Exploit Ease: No known exploits are available

Vulnerability Publication Date: 9/29/2026

Reference Information

CVE: CVE-2026-75804

Detections

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