PuTTY up to 0.83 RSA KEX double free

Summaryinfo

A vulnerability, which was classified as problematic, has been found in PuTTY up to 0.83. The affected element is an unknown function of the component RSA KEX Handler. This manipulation causes double free. The identification of this vulnerability is CVE-2026-48850. It is possible to initiate the attack remotely. There is no exploit available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in PuTTY up to 0.83. It has been declared as problematic. Affected by this vulnerability is an unknown functionality of the component RSA KEX Handler. The manipulation with an unknown input leads to a double free vulnerability. The CWE definition for the vulnerability is CWE-415. The product calls free() twice on the same memory address, potentially leading to modification of unexpected memory locations. As an impact it is known to affect availability.

The advisory is shared at lists.tartarus.org. This vulnerability is known as CVE-2026-48850 since 05/25/2026. The exploitation appears to be difficult. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Neither technical details nor an exploit are publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 316790 (Linux Distros Unpatched Vulnerability : CVE-2026-48850), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 0.84 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (316790). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

• Connectivity Software

Name

• PuTTY

Version

• 0.1
• 0.2
• 0.3
• 0.4
• 0.5
• 0.6
• 0.7
• 0.8
• 0.9
• 0.10
• 0.11
• 0.12
• 0.13
• 0.14
• 0.15
• 0.16
• 0.17
• 0.18
• 0.19
• 0.20
• 0.21
• 0.22
• 0.23
• 0.24
• 0.25
• 0.26
• 0.27
• 0.28
• 0.29
• 0.30
• 0.31
• 0.32
• 0.33
• 0.34
• 0.35
• 0.36
• 0.37
• 0.38
• 0.39
• 0.40
• 0.41
• 0.42
• 0.43
• 0.44
• 0.45
• 0.46
• 0.47
• 0.48
• 0.49
• 0.50
• 0.51
• 0.52
• 0.53
• 0.54
• 0.55
• 0.56
• 0.57
• 0.58
• 0.59
• 0.60
• 0.61
• 0.62
• 0.63
• 0.64
• 0.65
• 0.66
• 0.67
• 0.68
• 0.69
• 0.70
• 0.71
• 0.72
• 0.73
• 0.74
• 0.75
• 0.76
• 0.77
• 0.78
• 0.79
• 0.80
• 0.81
• 0.82
• 0.83

License

• open-source

CPE 2.3info

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CPE 2.2info

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Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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