What’s Vulnerable › Vulnerabilities

CVE-2019-9895

• Severity: critical (CVSS 9.8 v3.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 2.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2019-03-21 · updated 2026-06-17
• Weakness: CWE-119

Description

In PuTTY versions before 0.71 on Unix, a remotely triggerable buffer overflow exists in any kind of server-to-client forwarding.

Affected products

• Fedoraproject Fedora: 28, 29
• PuTTY: before 0.71 — fixed in 0.71

How to fix

Upgrade to a fixed version: PuTTY 0.71. Check the vendor advisory for mitigations.

References

• http://lists.opensuse.org/opensuse-security-announce/2019-04/msg00004.html
• http://lists.opensuse.org/opensuse-security-announce/2019-04/msg00020.html
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/36LWQ3NPFIV7DC7TC4KFPRYRH2OR7SZ2/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LDO3F267P347E6U2IILFCYW7JPTLCCES/
• https://seclists.org/bugtraq/2019/Apr/6
• https://security.netapp.com/advisory/ntap-20190404-0001/
• https://www.chiark.greenend.org.uk/~sgtatham/putty/changes.html
• https://www.debian.org/security/2019/dsa-4423
• http://lists.opensuse.org/opensuse-security-announce/2019-04/msg00004.html
• http://lists.opensuse.org/opensuse-security-announce/2019-04/msg00020.html
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/36LWQ3NPFIV7DC7TC4KFPRYRH2OR7SZ2/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LDO3F267P347E6U2IILFCYW7JPTLCCES/

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