CVE-2026-4115

PuTTY Ed25519 Signature ecc-ssh.c eddsa_verify signature verification

LOW
3.7
CVSS Score
Published: March 22, 2026 at 12:15 PM UTC
Updated: June 17, 2026 at 10:56 AM UTC
1 product affected across 1 vendorPuTTY

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Severity
LOW3.7
Exploit prediction
EPSS 0.6%
SSVC
PoC

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 弱身份验证. 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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (9)

VDB EntryTechnical DescriptionThird Party Advisory
Source: cverecord
https://vuldb.com/?id.352429
SignaturePermissions RequiredVDB Entry
Source: cverecord
https://vuldb.com/?ctiid.352429
Third Party AdvisoryVDB Entry
Source: cverecord
https://vuldb.com/?submit.775576
RelatedThird Party Advisory
Source: cverecord
https://github.com/py-thok/putty-ed25519-malleability-s-plus-l
RelatedTechnical Description
Source: cverecord
https://www.rfc-editor.org/rfc/rfc8032#section-8.4

SSVC — Action Prioritization

SSVCPoCNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

3.7LOWVulDB
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-347CWE-345

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