Security readout for executives and security teams
PuTTY 0.83 has a reported Ed25519 signature verification flaw. The sources say exploitation would be remote but difficult, and the real-world impact is currently unproven and disputed. A public proof of concept exists, and a vendor patch is identified, so affected organizations should patch without treating this as a confirmed active-attack emergency. Exposure appears limited to environments running PuTTY 0.83 where Ed25519 signature verification is reachable. The supplied sources do not identify other affected products, configurations, or confirmed operational impact. Patch during the next normal security maintenance window unless PuTTY 0.83 is widely used in sensitive administrative workflows. Escalate if vendor guidance later confirms practical impact or active exploitation. Mitigation focus: Identify all PuTTY 0.83 installations and managed packages.; Apply the vendor patch or a vendor-provided fixed PuTTY release.; Prioritize internet-facing or high-trust administrative workstations using PuTTY..
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-345: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCWE-347: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2026-4115 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 6.3 (4.0)
- Known Exploited
- No
- Published
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
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
4 official scoresWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
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——VulDBCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N/E:P/RL:O/RC:C2.21.4VulDBCVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N/E:P/RL:O/RC:C2.21.4VulDBAV:N/AC:H/Au:N/C:N/I:P/A:N/E:POC/RL:OF/RC:C4.92.9VulDBVulnerability scoring details
Base CVSS 4.0 score
6.3MediumVector: 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
Base CVSS 3.1 score
3.7LowVector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N/E:P/RL:O/RC:C
Base CVSS 3.0 score
3.7LowVector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N/E:P/RL:O/RC:C
Base CVSS 2.0 score
2.6LowVector: AV:N/AC:H/Au:N/C:N/I:P/A:N/E:POC/RL:OF/RC:C
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- Source timelineVulDB
Advisory disclosed
- Source timelineVulDB
VulDB entry created
- CVE publishedCVE Program
The CVE record was published.
- Source timelineVulDB
VulDB entry last update
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- VDB-352429 | PuTTY Ed25519 Signature ecc-ssh.c eddsa_verify signature verificationCVE reference, VulDB · vdb-entry, technical-description
- VDB-352429 | CTI Indicators (IOB, IOC, IOA)CVE reference, VulDB · signature, permissions-required
- Submit #775576 | PuTTY Project (Simon Tatham) PuTTY 0.83 Improper Verification of Cryptographic SignatureCVE reference, VulDB · third-party-advisory
- https://github.com/py-thok/putty-ed25519-malleability-s-plus-lCVE reference, VulDB · related
- https://www.chiark.greenend.org.uk/~sgtatham/putty/wishlist/eddsa-overlarge-s.htmlCVE reference, VulDB · related
- https://github.com/py-thok/putty-ed25519-malleability-s-plus-l/blob/main/poc.pyCVE reference, VulDB · exploit
- https://git.tartarus.org/?p=simon/putty.git;a=commitdiff;h=af996b5ec27ab79bae3882071b9d6acf16044549CVE reference, VulDB · patch
- https://www.rfc-editor.org/rfc/rfc8032#section-8.4CVE reference, VulDB · related
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Insufficient Verification of Data Authenticity
Insufficient Verification of Data Authenticity represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
Improper Verification of Cryptographic Signature
Improper Verification of Cryptographic Signature represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.