NVD / CVE Program· CNA VulnCheck

CVE-2026-80155: Lantronix Autonomous Out-of-Band Devices Unauthenticated Authentication Bypass via snprintf Path Truncation

CriticalCVSS 10.0 · v4.0—No exploit No fix recorded

Noroxi assessment

Priority: Plan (action score 40/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 1% (FIRST EPSS); higher than 63.9% of all records.
Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
According to CISA the attack is automatable: targets can be found by mass scanning.
According to the record, no fixed version is available yet.
Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Add it to your regular patch cycle. Update when a fix is released; follow the vendor's advisory.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

EUVD-2026-84521

Published: Sep 22, 2026
Updated: Sep 24, 2026
EPSS: 1.0% · 63th percentile
CWE: CWE-22

Report tools

JSON

Action score

Plan

Add it to your regular patch cycle.

CVSS: 40 / 40 · 10.0 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 1.0%

CISA SSVC decision

Exploitation: none
Automatable: yes
Technical impact: total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: —
CNA · VulnCheck: 10.0; NVD has not scored this yet; the score shown is the CNA’s.

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

Not in KEV: no record of exploitation in the wild
No public exploit code on record
No fixed version yet

If any of these changes, we'll tell you in the daily email digest.

Is your version affected? Check it

Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

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Versions reported by the vendor

Affected version ranges reported by the assigning authority (VulnCheck). Independent of NVD's CPE analysis and usually ahead of it.

LANTRONIX EMG7500
- before 9.7.0.1affected
LANTRONIX EMG8500
- before 9.7.0.1affected
LANTRONIX SLB882
- all versionsaffected
LANTRONIX SLC8000
- before 9.7.0.5affected
LANTRONIX SLC9000
- before 9.7.0.2affected
LANTRONIX SLCx-02
- all versionsaffected
LANTRONIX SLCx-03
- all versionsaffected

Same product

lantronix: all records

Other highest-scoring records for the same primary product.

CVE-2026-80145Lantronix Autonomous Out-of-Band Devices CLI Command Injection via set cifs password
38Monitor
CVE-2026-80144Lantronix Autonomous Out-of-Band Devices CLI Command Injection via mfc eeprom write
38Monitor
CVE-2026-80143Lantronix Autonomous Out-of-Band Devices CLI Command Injection via mfc eeprom read
38Monitor

Published before and after this one in the same product

← EarlierCVE-2026-80152Sep 22, 2026 · Lantronix Autonomous Out-of-Band Devices OS Command Injection via set script schedule
37Monitor
← EarlierCVE-2026-80154Sep 22, 2026 · Lantronix Autonomous Out-of-Band Devices Predictable Session Token with Validation Bypass
35Monitor
Later →CVE-2026-80156Sep 22, 2026 · Lantronix Autonomous Out-of-Band Devices Arbitrary File Write via Upload Filename Validation Bypass
37Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

No fix version is recorded for this entry. Check the references for vendor advisories.

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days-1% in 7 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

RE/VRbfinder

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

CVE-2026-801560 days apartLantronix Autonomous Out-of-Band Devices Arbitrary File Write via Upload Filename Validation Bypass
37Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

CVE-2026-801450 days apartLantronix Autonomous Out-of-Band Devices CLI Command Injection via set cifs password
38Monitor
CVE-2026-801510 days apartLantronix Autonomous Out-of-Band Devices OS Command Injection via set nfs download
37Monitor
CVE-2026-801520 days apartLantronix Autonomous Out-of-Band Devices OS Command Injection via set script schedule
37Monitor
CVE-2026-801560 days apartLantronix Autonomous Out-of-Band Devices Arbitrary File Write via Upload Filename Validation Bypass
37Monitor

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

TR-26-1154 · Sep 23, 2026(Lantronix Çoklu Ürün Güvenlik Bildirimi)

All national notices →

Not on record for this CVE: patch commit or PR link · public bounty program.

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
No account or password is required.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality
Integrity
Availability

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: X

Weakness class (CWE)

CWE-22 · Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

nvd-secondary

Root cause

A user-supplied file name is joined with the allowed directory, but the result is never checked to confirm it is still inside that directory.

The bug in code

The whole CWE-22 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1const file = path.join(ROOT, req.query.name);
2res.sendFile(file);

Fixed

1const file = path.resolve(ROOT, req.query.name);
2if (!file.startsWith(ROOT + path.sep)) {
3  return res.sendStatus(400);
4}
5res.sendFile(file);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Attack patterns (CAPEC)

ATT&CK techniques

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Change log (0)

No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.

References

revrb.net/2026/09/21/revrb-lantern.html

Show all references (5 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records