CVE-2025-9817 NULL Pointer Dereference in Wireshark

High 7.8 Published Updated

A NULL pointer dereference in the SSH dissector allows attackers to cause a denial of service in Wireshark.

Exploited in the wild
Not known
Login needed
Not needed
Attackable
Local or same network only
Victim action needed
A user has to click or open something
Fix
Available

What is CVE-2025-9817?

CVE-2025-9817 is a high-severity vulnerability in Wireshark Wireshark, published on 3 Sep 2025. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

Official description

SSH dissector crash in Wireshark 4.4.0 to 4.4.8 allows denial of service

Weakness: CWE-476

Which versions are affected by CVE-2025-9817?

It affects 1 product.

Linux distribution packages (22)
wireshark AlmaLinux:10All versions1:4.4.2-4.el10_1.2
wireshark-cli AlmaLinux:10All versions1:4.4.2-4.el10_1.2
wireshark-devel AlmaLinux:10All versions1:4.4.2-4.el10_1.2
wireshark Red Hat:enterprise_linux:10.1All versions1:4.4.2-4.el10_1.2
wireshark-cli Red Hat:enterprise_linux:10.1All versions1:4.4.2-4.el10_1.2
wireshark-cli-debuginfo Red Hat:enterprise_linux:10.1All versions1:4.4.2-4.el10_1.2
wireshark-debuginfo Red Hat:enterprise_linux:10.1All versions1:4.4.2-4.el10_1.2
wireshark-debugsource Red Hat:enterprise_linux:10.1All versions1:4.4.2-4.el10_1.2
wireshark-devel Red Hat:enterprise_linux:10.1All versions1:4.4.2-4.el10_1.2
wireshark Red Hat:enterprise_linux_eus:10.0All versions1:4.4.2-3.el10_0.2
wireshark-cli Red Hat:enterprise_linux_eus:10.0All versions1:4.4.2-3.el10_0.2
wireshark-cli-debuginfo Red Hat:enterprise_linux_eus:10.0All versions1:4.4.2-3.el10_0.2
wireshark-debuginfo Red Hat:enterprise_linux_eus:10.0All versions1:4.4.2-3.el10_0.2
wireshark-debugsource Red Hat:enterprise_linux_eus:10.0All versions1:4.4.2-3.el10_0.2
wireshark-devel Red Hat:enterprise_linux_eus:10.0All versions1:4.4.2-3.el10_0.2
wireshark Rocky Linux:10All versions1:4.4.2-4.el10_1.2
wireshark SUSE:Linux Enterprise Module for Basesystem 15 SP6All versions4.2.13-150600.18.26.1
wireshark SUSE:Linux Enterprise Module for Basesystem 15 SP7All versions4.2.13-150600.18.26.1
wireshark SUSE:Linux Enterprise Module for Desktop Applications 15 SP6All versions4.2.13-150600.18.26.1
wireshark SUSE:Linux Enterprise Module for Desktop Applications 15 SP7All versions4.2.13-150600.18.26.1
wireshark openSUSE:Leap 15.6All versions4.2.13-150600.18.26.1
wireshark openSUSE:TumbleweedAll versions4.4.9-2.1

Products include Wireshark Wireshark.

How do I fix CVE-2025-9817?

Upgrade to a fixed version.

Is CVE-2025-9817 being exploited?

There is no known exploitation of CVE-2025-9817 in the wild and no public exploit code.

All Wireshark Wireshark vulnerabilities

Sources

Also known as ALSA-2026:1714, AZL-66770, DEBIAN-CVE-2025-9817, GHSA-3mqq-9w3m-xpj8, OESA-2025-2263, OESA-2025-2264 and 9 more.

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