Evidence used
- No CISA KEV confirmation is currently recorded.
- The selected CVSS metric records a network-reachable, unauthenticated path with no user interaction.
- EPSS is 1.03% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2026
CVE-2026-80155High confidence
Lantronix Autonomous Out-of-Band Devices Unauthenticated Authentication Bypass via snprintf Path Truncation
LANTRONIX · SLC8000
10.0CriticalCVSS 4.0
Within 72 hours
Patch availableCritical technical impact with a remotely reachable, unauthenticated path; no CISA KEV confirmation is currently recorded.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityCritical→Operational priority:Critical, unchanged from published severity.unchanged
Compensating controls
- Validate the affected product branch and deploy the verified fixed release.
- Restrict the affected network interface to trusted sources where business-safe.
- Monitor vendor guidance and exploitation sources for a material change.
Verification
- Confirm that the asset runs LANTRONIX SLC8000 and falls inside the recorded affected range.
- Verify the installed build against the product-specific fixed version after deployment.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Critical technical impact with a remotely reachable, unauthenticated path; no CISA KEV confirmation is currently recorded.
Patch available01
What, why and how
Lantronix SLC8000 before firmware v9.7.0.5, SLC9000 before firmware v9.7.0.2, EMG8500/EMG7500 before firmware v9.7.0.1, and all firmware versions of SLB882/SLCx-03/SLCx-02 contain an authentication bypass vulnerability in the web management portal upload endpoint that allows unauthenticated attackers to read sensitive configuration files and upload files to arbitrary filesystem locations, leading to remote code execution. The web configuration server constructs the session cookie file path using snprintf with a fixed-size buffer; by supplying a cookie value of a specific length an attacker causes the path to truncate at the required delimiter and leverages path traversal to redirect authentication validation to an arbitrary on-disk file such as the local user database, bypassing all session checks. Attackers can use this vulnerability to achieve complete loss of confidentiality, integrity, and availability on the affected device and potentially impact downstream serial-connected devices.
What
Lantronix SLC8000 before firmware v9.7.0.5, SLC9000 before firmware v9.7.0.2, EMG8500/EMG7500 before firmware v9.7.0.1, and all firmware versions of SLB882/SLCx-03/SLCx-02 contain an authentication bypass vulnerability in the web management portal upload endpoint that allows unauthenticated attackers to read sensitive configuration files and upload files to arbitrary filesystem locations, leading to remote code execution. The web configuration server constructs the session cookie file path using snprintf with a fixed-size buffer; by supplying a cookie value of a specific length an attacker causes the path to truncate at the required delimiter and leverages path traversal to redirect authentication validation to an arbitrary on-disk file such as the local user database, bypassing all session checks. Attackers can use this vulnerability to achieve complete loss of confidentiality, integrity, and availability on the affected device and potentially impact downstream serial-connected devices.
Why
Attacker-controlled path data is not constrained to the intended directory before the application accesses a file.
How
An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may execute code or commands in the affected security context.
What
Lantronix SLC8000 before firmware v9.7.0.5, SLC9000 before firmware v9.7.0.2, EMG8500/EMG7500 before firmware v9.7.0.1, and all firmware versions of SLB882/SLCx-03/SLCx-02 contain an authentication bypass vulnerability in the web management portal upload endpoint that allows unauthenticated attackers to read sensitive configuration files and upload files to arbitrary filesystem locations, leading to remote code execution. The web configuration server constructs the session cookie file path using snprintf with a fixed-size buffer; by supplying a cookie value of a specific length an attacker causes the path to truncate at the required delimiter and leverages path traversal to redirect authentication validation to an arbitrary on-disk file such as the local user database, bypassing all session checks. Attackers can use this vulnerability to achieve complete loss of confidentiality, integrity, and availability on the affected device and potentially impact downstream serial-connected devices.
Why
Attacker-controlled path data is not constrained to the intended directory before the application accesses a file.
How
An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may execute code or commands in the affected security context.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation No confirmed evidence
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
Public PoC / exploit material None recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.
- Likely attack path
- a network path → Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') → execute code or commands in the affected security context
- Attack surface
- Network
- Privileges required
- None: unauthenticated exploitation is possible
- User interaction
- None
- Attack complexity
- Low: no specialised conditions are recorded
- Security boundary
- Not a CVSS 4.0 base metric
- Weakness
?
CWE means Common Weakness Enumeration: a standard category for the underlying weakness. - CWE-22 ↗
CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal'). The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.
- CVSS vector
?
CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity. CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:HCommon Vulnerability Scoring System 4.0: the compact vector below is decoded into plain language.
AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.ATNoneAttack requirements: No additional deployment or execution condition is required.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.VCHighVulnerable-system confidentiality: A successful attack can cause a major loss.VIHighVulnerable-system integrity: A successful attack can cause a major loss.VAHighVulnerable-system availability: A successful attack can cause a major loss.SCHighSubsequent-system confidentiality: A successful attack can cause a major loss.SIHighSubsequent-system integrity: A successful attack can cause a major loss.SAHighSubsequent-system availability: A successful attack can cause a major loss.- Post-exploitation / living off the land
- After compromise, an attacker may use built-in shells, scripting engines, scheduled tasks and native network utilities for discovery, persistence or movement. This is a plausible LoTL path, not evidence that it has occurred for every attack.
03
Patch and workaround
Operational remediation based on structured source evidence.
- Status
?
Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change. - Patch available
- Affected
- Action
- Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
- Workaround
- No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04
Evidence and provenance
Published 22 Sept 2026 · Last source change 24 Sept 2026, 19:11 UTC · CWE-22 · Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source FIRST · tracked since 2026-09-23
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2026-84521
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD awaiting enrichment
Core structured fields are present and their contributing authorities are shown above.
Material change intelligence
View recent updates ↗What changed after publication
- Vendor guidanceAuthoritative vendor guidance changed: removed patch: ts.lantronix.com/9.7.0.2R1; removed remediation: ts.lantronix.com/9.7.0.2R1.CNA ↗
- Before
- patch: ts.lantronix.com/9.7.0.2R1 · remediation: ts.lantronix.com/9.7.0.2R1
- After
- no authoritative guidance recorded
- Affected versionsThe structured affected or fixed version information changed.CNA ↗
- Before
- SLC8000: < 9.7.0.5; EMG8500: < 9.7.0.1; EMG7500: < 9.7.0.1; SLB882: *; SLCx-03: *; SLCx-02: *; SLC9000: < 9.7.0.2 · Fixed: An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
- After
- SLC8000: < 9.7.0.5; EMG8500: < 9.7.0.1; EMG7500: < 9.7.0.1; SLB882: *; SLCx-03: *; SLCx-02: *; SLC9000: < 9.7.0.2 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
- Remediation statusRemediation status changed from Patch available to Awaiting fix.CNA ↗
- Before
- Patch available
- After
- Awaiting fix
- Vendor guidanceAuthoritative vendor guidance changed: added patch: ts.lantronix.com/9.7.0.2R1; added remediation: ts.lantronix.com/9.7.0.2R1.ts.lantronix.com ↗
- Before
- no authoritative guidance recorded
- After
- patch: ts.lantronix.com/9.7.0.2R1 · remediation: ts.lantronix.com/9.7.0.2R1
- Affected versionsThe structured affected or fixed version information changed.CNA ↗
- Before
- SLC8000: < 9.7.0.5; EMG8500: < 9.7.0.1; EMG7500: < 9.7.0.1; SLB882: *; SLCx-03: *; SLCx-02: * · Fixed: No fixed version is explicitly recorded in the structured CVE data.
- After
- SLC8000: < 9.7.0.5; EMG8500: < 9.7.0.1; EMG7500: < 9.7.0.1; SLB882: *; SLCx-03: *; SLCx-02: *; SLC9000: < 9.7.0.2 · Fixed: An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
- Remediation statusRemediation status changed from Awaiting fix to Patch available.ts.lantronix.com ↗
- Before
- Awaiting fix
- After
- Patch available
- ENISA EUVD mappingEUVD-2026-84521 was added to the official ENISA EUVD mapping for this CVE.ENISA EUVD ↗
- Before
- not recorded
- After
- {"euvdId":"EUVD-2026-84521"}
- Catalogue recordCVE added to the BlackTree catalogue.CNA ↗
Technical terms and abbreviations used in this report
- CVE
- Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
- CVSS
- Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
- EPSS
- Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
- CWE
- Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
- CNA
- CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
- CISA ADP
- Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
- NVD
- National Vulnerability Database: NIST's enrichment service for CVE records.
- CERT / CSIRT
- A computer security incident response team that publishes warnings or coordinates incident response.
- PoC
- Proof of concept: public material that demonstrates or helps reproduce exploitation.
- CSAF
- Common Security Advisory Framework: a machine-readable format for security advisories.
- LoTL
- Living off the land: abuse of legitimate tools or system functions during an attack.