CVE-2019-9897 Denial of service in n/a

What is CVE-2019-9897?

CVE-2019-9897 is a high-severity denial of service vulnerability in Debian Debian Linux, published on 21 Mar 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

Multiple denial-of-service attacks that can be triggered by writing to the terminal exist in PuTTY versions before 0.71.

Which versions are affected by CVE-2019-9897?

It affects 5 products.

Products include Debian Debian Linux, Fedoraproject Fedora, Netapp Oncommand Unified Manager, Opensuse Leap, Putty Putty.

How do I fix CVE-2019-9897?

Upgrade to a fixed version.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2019-9897 being exploited?

There is no known exploitation of CVE-2019-9897 in the wild and no public exploit code.

Other vulnerabilities in Debian Debian Linux

• CVE-2015-3306 ProFTPD Improper Access Control Exploited Critical 10.0
• CVE-2025-49113 RoundCube Webmail Deserialization of Untrusted Data Exploited Critical 9.9
• CVE-2026-24061 GNU InetUtils Argument Injection Exploited Critical 9.8
• CVE-2025-39682 Linux Kernel Improper Check for Unusual or Exceptional Conditions Exploited Critical 9.8
• CVE-2024-9680 Mozilla Firefox Use-After-Free Exploited Critical 9.8

All Debian Debian Linux vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as ALPINE-CVE-2019-9897, DEBIAN-CVE-2019-9897, GHSA-8428-8q8v-98pj, UBUNTU-CVE-2019-9897.