A vulnerability was found in PuTTY 0.83 . It has been declared as problematic . 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. This vulnerability was named CVE-2026-4115 . The attack may be performed from remote. In addition, an exploit is available. The real existence of this vulnerability is still doubted at the moment. It is advisable to implement a pa
Full text archived locally
✦ AI Summary· Claude Sonnet
VDB-352429 · CVE-2026-4115 · EUVD-2026-14301
PUTTY 0.83 ED25519 SIGNATURE CRYPTO/ECC-SSH.C EDDSA_VERIFY SIGNATURE VERIFICATION ⚔ [DISPUTED]
HISTORYDIFFRELATEJSONXMLCTI
CVSS Meta Temp Score Current Exploit Price (≈) CTI Interest Score
3.4 $0-$5k 2.89
Summaryinfo
A vulnerability was found in PuTTY 0.83. It has been rated as problematic. Affected by this vulnerability is the function eddsa_verify of the file crypto/ecc-ssh.c of the component Ed25519 Signature Handler. This manipulation causes signature verification. The identification of this vulnerability is CVE-2026-4115. It is possible to initiate the attack remotely. Furthermore, there is an exploit available. It is still unclear if this vulnerability genuinely exists. Applying a patch is the recommended action to fix 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.
Detailsinfo
A vulnerability was found in PuTTY 0.83. It has been declared as problematic. Affected by this vulnerability is the function eddsa_verify of the file crypto/ecc-ssh.c of the component Ed25519 Signature Handler. The manipulation with an unknown input leads to a signature verification vulnerability. The CWE definition for the vulnerability is CWE-347. The product does not verify, or incorrectly verifies, the cryptographic signature for data. As an impact it is known to affect integrity.
The advisory is shared at github.com. This vulnerability is known as CVE-2026-4115. The exploitation appears to be difficult. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details and also a public exploit are known.
It is possible to download the exploit at github.com. It is declared as proof-of-concept. The real existence of this vulnerability is still doubted at the moment. 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.
Applying the patch af996b5ec27ab79bae3882071b9d6acf16044549 is able to eliminate this problem. The bugfix is ready for download at git.tartarus.org.
The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-14301). Additional details are provided at rfc-editor.org.
Productinfo
Type
Connectivity Software
Name
PuTTY
Version
0.83
License
open-source
CPE 2.3info
🔒
CPE 2.2info
🔒
CVSSv4info
VulDB Vector: 🔒
VulDB Reliability: 🔍
CVSSv3info
VulDB Meta Base Score: 3.7
VulDB Meta Temp Score: 3.4
VulDB Base Score: 3.7
VulDB Temp Score: 3.4
VulDB Vector: 🔒
VulDB Reliability: 🔍
CVSSv2info
Vector Complexity Authentication Confidentiality Integrity Availability
Unlock Unlock Unlock Unlock Unlock Unlock
Unlock Unlock Unlock Unlock Unlock Unlock
Unlock Unlock Unlock Unlock Unlock Unlock
VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍
Exploitinginfo
Class: Signature verification
CWE: CWE-347 / CWE-345
CAPEC: 🔒
ATT&CK: 🔒
Physical: No
Local: No
Remote: Yes
Availability: 🔒
Access: Public
Status: Proof-of-Concept
Programming Language: 🔒
Download: 🔒
Price Prediction: 🔍
Current Price Estimation: 🔒
0-Day Unlock Unlock Unlock Unlock
Today Unlock Unlock Unlock Unlock
Threat Intelligenceinfo
Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍
Countermeasuresinfo
Recommended: Patch
Status: 🔍
0-Day Time: 🔒
Patch: af996b5ec27ab79bae3882071b9d6acf16044549
Timelineinfo
03/22/2026 Advisory disclosed
03/22/2026 +0 days VulDB entry created
03/22/2026 +0 days VulDB entry last update
Sourcesinfo
Advisory: github.com
Status: Confirmed
Confirmation: 🔒
Disputed: 🔍
CVE: CVE-2026-4115 (🔒)
GCVE (CVE): GCVE-0-2026-4115
GCVE (VulDB): GCVE-100-352429
EUVD: 🔒
scip Labs: https://www.scip.ch/en/?labs.20161013
Misc.: 🔒
Entryinfo
Created: 03/22/2026 12:53
Updated: 03/22/2026 15:36
Changes: 03/22/2026 12:53 (63), 03/22/2026 12:54 (1), 03/22/2026 15:36 (1)
Complete: 🔍
Submitter: pythok
Cache ID: 99:A76:101
Submitinfo
Accepted
Submit #775576: PuTTY Project (Simon Tatham) PuTTY 0.83 Improper Verification of Cryptographic Signature (by pythok)
Discussion
No comments yet. Languages: en.
Please log in to comment.
◂ PreviousOverviewNext ▸