Answer in brief
CVE-2026-67191 records a Unknown severity vulnerability in Xlight FTP Server < 3.9.5 Pre-Auth Heap Buffer Overflow via SSH Parser. The current sources do not mark it as known exploited. The current feed maps Xlight/Xlight FTP Server (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Xlight/Xlight FTP Server (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Xlight/Xlight FTP Servergeneric | >=0 <3.9.5 | 3.9.5 |
Published upstream
Jul 29, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 14, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 14, 2026
Xlight FTP Server before 3.9.5 contains a pre-authentication heap buffer overflow vulnerability that allows remote unauthenticated attackers to write past the end of a heap buffer by sending a malformed SSH client identification string. A logic error in the recv loop's termination condition uses an incorrect OR operator where an AND operator is required, enabling exploitation on any SSH or SFTP connection before authentication occurs.
Quoted source text, attributed separately from HOL analysis.
Answer in brief
CVE-2026-67191 records a Unknown severity vulnerability in Xlight FTP Server < 3.9.5 Pre-Auth Heap Buffer Overflow via SSH Parser. The current sources do not mark it as known exploited. The current feed maps Xlight/Xlight FTP Server (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Xlight/Xlight FTP Server (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Xlight/Xlight FTP Servergeneric | >=0 <3.9.5 | 3.9.5 |
Published upstream
Jul 29, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 14, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 14, 2026
Xlight FTP Server before 3.9.5 contains a pre-authentication heap buffer overflow vulnerability that allows remote unauthenticated attackers to write past the end of a heap buffer by sending a malformed SSH client identification string. A logic error in the recv loop's termination condition uses an incorrect OR operator where an AND operator is required, enabling exploitation on any SSH or SFTP connection before authentication occurs.
Quoted source text, attributed separately from HOL analysis.