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National Vulnerability Database

National Vulnerability Database

NVD

National Vulnerability Database
  1. Vulnerabilities

CVE-2026-4115 Detail

Disputed     

Description

A vulnerability was detected in PuTTY 0.83. Affected is the function eddsa_verify of the file crypto/ecc-ssh.c of the component Ed25519 Signature Handler. The manipulation results in improper verification of cryptographic signature. The attack may be performed from remote. The attack requires a high level of complexity. The exploitability is told to be difficult. The exploit is now public and may be used. The real existence of this vulnerability is still doubted at the moment. The patch is identified as af996b5ec27ab79bae3882071b9d6acf16044549. It is advisable to implement a patch to correct this issue. The vendor was contacted early, responded in a very professional manner and quickly released a patch for the affected product. However, at the moment there is no proof that this flaw might have any real-world impact.


Metrics

 
NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

Nist CVSS score does not match with CNA score
CNA:  VulDB
CVSS-BT 2.9 LOW
Vector:  CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P

References to Advisories, Solutions, and Tools

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URL Source(s) Tag(s)
https://git.tartarus.org/?p=simon/putty.git;a=commitdiff;h=af996b5ec27ab79bae3882071b9d6acf16044549 VulDB Permissions Required 
https://github.com/py-thok/putty-ed25519-malleability-s-plus-l VulDB Third Party Advisory 
https://github.com/py-thok/putty-ed25519-malleability-s-plus-l/blob/main/poc.py VulDB Exploit 
https://vuldb.com/?ctiid.352429 VulDB Permissions Required  VDB Entry 
https://vuldb.com/?id.352429 VulDB Third Party Advisory  VDB Entry 
https://vuldb.com/?submit.775576 VulDB Third Party Advisory  VDB Entry 
https://www.chiark.greenend.org.uk/~sgtatham/putty/wishlist/eddsa-overlarge-s.html VulDB Third Party Advisory 
https://www.rfc-editor.org/rfc/rfc8032#section-8.4 VulDB Technical Description 

Weakness Enumeration

CWE-ID CWE Name Source
CWE-345 Insufficient Verification of Data Authenticity VulDB  
CWE-347 Improper Verification of Cryptographic Signature VulDB  

Known Affected Software Configurations Switch to CPE 2.2

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Denotes Vulnerable Software
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Change History

3 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2026-4115
NVD Published Date:
03/22/2026
NVD Last Modified:
04/30/2026
Source:
VulDB