Security readout for executives and security teams
Plain-English summary
Xlight FTP Server versions before 3.9.5 can be attacked remotely before login when SSH uses a GCM cipher. A malformed packet may corrupt server memory and potentially let an attacker run code, threatening confidentiality, integrity, and availability. Internet-accessible servers are the highest priority.
Executive priority
Treat exposed pre-3.9.5 servers as an emergency remediation item because compromise may occur before authentication and affect the entire host. Prioritize internet-facing systems, upgrade promptly, and restrict access while remediation proceeds. There is no supplied evidence of active exploitation, but the potential impact justifies immediate action.
Technical view
An unvalidated SSH packet length is passed to the GCM decryption function, causing a pre-authentication stack buffer overflow. The reported overwrite can reach the stack cookie and return address, creating potential remote-code-execution impact. CVE-2026-67192 is rated 9.2 under CVSS 4.0 and categorized as CWE-121.
Likely exposure
Exposure requires Xlight FTP Server earlier than 3.9.5, reachable SSH functionality, and GCM cipher negotiation. Publicly reachable services present the greatest risk. The bundle does not identify affected operating systems, default cipher settings, deployment prevalence, or reliable external fingerprinting methods.
Exploitation context
The vulnerability is remotely reachable without credentials and has low stated attack complexity, although the CVSS vector records an attack requirement. The supplied record is not in KEV, and no cited evidence establishes active exploitation. Potential remote code execution is reported, but exploit reliability and observed campaigns are not documented.
Researcher notes
The source bundle describes control of stack memory through an unchecked length passed into GCM decryption. It does not provide enough evidence to determine exploit reliability, platform-specific protections, affected build boundaries beyond “before 3.9.5,” detection signatures, or whether GCM is enabled by default. Validate safely in an isolated environment without testing production services.
Mitigation direction
- Upgrade Xlight FTP Server to version 3.9.5 or later following vendor guidance.
- Restrict SSH service access to trusted networks until upgrading is complete.
- Remove unnecessary internet exposure using firewall or access-control rules.
- Check the vendor changelog and advisory for additional configuration guidance.
Validation and detection
- Inventory Xlight FTP Server instances and record their exact installed versions.
- Confirm every instance is version 3.9.5 or later.
- Identify whether SSH is enabled, reachable, and permits GCM cipher negotiation.
- Review network exposure and verify temporary access restrictions are effective.
- Inspect available service and system logs for unexplained crashes or abnormal SSH connections.
Public sources used
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-121: 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 lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-67192 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
- Critical
- CVSS
- 9.2 (4.0)
- Known Exploited
- No
- Published
Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
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
2 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:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N——VulnCheckCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H2.25.9VulnCheckVulnerability scoring details
Base CVSS 4.0 score
9.2CriticalVector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Base CVSS 3.1 score
8.1HighVector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
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.
- CVE publishedCVE Program
The CVE record was published.
- 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
- ChangelogCVE reference, VulnCheck · release-notes
- https://www.vulncheck.com/advisories/xlight-ftp-server-pre-auth-stack-buffer-overflow-via-ssh-gcm-cipherCVE reference, VulnCheck · third-party-advisory
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.
Stack-based Buffer Overflow
Stack-based Buffer Overflow represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.