CVE Intelligence
Medium File handling

CVE-2026-12339 — Authenticated Arbitrary File Write Vulnerability in multiple devices

A Zip Slip vulnerability in the WebUI ISP Upgrade functionality allows arbitrary file write via a crafted archive containing directory traversal sequences. An authenticated administrator may overwrite arbitrary files on the system.Successful exploitation may allow arbitrary file to be overwritten on the underlying system, affecting system integrity and availability.

Published Aug 10, 2026 · Updated Oct 15, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: TPLink

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.
How the score was calculated
  • Technical severity (medium)+3

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
—
No EPSS score.
Affects
TP-Link Systems Inc.
Archer MR200 v7 and 5 more
CVSS base
6.9
Medium · 2 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation
None
none · proof-of-concept · active
Automatable
No
can an attacker script the kill-chain steps
Technical impact
Partial
partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

  1. Identify exposed assets running the affected vendor/product/version combinations (TP-Link Systems Inc. Archer MR200 v7, TP-Link Systems Inc. Archer MR600 v2, TP-Link Systems Inc. TL-MR100 v3.20…).
  2. No fix documented in the sources: reduce exposure and monitor the vendor advisory.
  3. Search available logs for exploit probes matching the vulnerability class (file handling), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
TP-Link Systems Inc. Archer MR200 v7 < (EU)_1.3.0 0.9.1 v0001.0 Build 260605 Rel.57870n Vulnerable CVE Program (cve.org) e CISA ADP
TP-Link Systems Inc. Archer MR600 v2 < (EU)_1.10.0 0.9.1 v0001.0 Build 260618 RC.40417n Vulnerable CVE Program (cve.org) e CISA ADP
TP-Link Systems Inc. TL-MR100 v3.20 < (EU)_1.3.0 0.9.1 v0001.0 Build 260609 Rel.49957n< 1.1.0 0.9.1 v0001.0 Build 260609 Rel35479n,  Customized Software for South Korea< 1.2.0 0.9.1 v0001.0 Build 260609 Rel.36250n, Customized Software for South Korea Vulnerable CVE Program (cve.org) e CISA ADP
TP-Link Systems Inc. TL-MR150 v3.20 < (EU)_1.3.0 0.9.1 v0001.0 Build 260720 Rel.59727n Vulnerable CVE Program (cve.org) e CISA ADP
TP-Link Systems Inc. TL-MR6400 v5.3 < (EU)_1.10.0 0.9.1 v0001.0 Build 260613 RC.76099n Vulnerable CVE Program (cve.org) e CISA ADP
TP-Link Systems Inc. TL-MR6400 v8.0 < (EU)_1.5.0 0.9.1 v0001.0 Build 260610 Rel.67978n Vulnerable CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector
Adjacent
Attack complexity
Low
Attack requirements
None
Privileges required
High
User interaction
None
Scope
X
Confidentiality (vulnerable system)
None
Integrity (vulnerable system)
High
Availability (vulnerable system)
Low
Confidentiality (subsequent)
None
Integrity (subsequent)
None
Availability (subsequent)
None

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactScored by
6.9 CVSS 4.0 Medium — — f23511db-6c3e-4e32-a477-6aa17d310630 via NIST National Vulnerability Database
6.9 CVSS 4.0 Medium — — TPLink via CVE Program (cve.org) e CISA ADP
CVSS:4.0/AV:A/AC:L/AT:N/PR:H/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N/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 (score shown at the top: f23511db-6c3e-4e32-a477-6aa17d310630)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-22 · Path Traversal

Other CVEs with this weakness →

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

  • Monitor file creation in web directories and paths with traversal sequences (../).
file integrity (FIM)endpoint telemetry (EDR)

Timeline

What happened to this CVE, newest first.

  • 2026
  • Affected products added · tp-link systems inc./tl-mr6400 v5.3, tp-link systems inc./archer mr600 v2, tp-link systems inc./archer mr200 v7, tp-link
    Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
  • SSVC assessment updated
    Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 15, 2026
  • CVSS changed · 6.9
    Oct 15, 2026 · NIST National Vulnerability Database
  • Source status changed · → Awaiting Analysis
    Oct 15, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 15, 2026 · NIST National Vulnerability Database
  • CVE published
    Aug 10, 2026 · TPLink

Source activity

Repeated readings are counted rather than listed.

  • 1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

8 on the record

Elsewhere on this site

TP-Link Systems Inc.
every CVE for this vendor
File handling
same class
CWE-22
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-75118 http_gdpr_decrypt Pre-Authentication Stack-Based Buffer Overflow Aug 28, 2026
  • CVE-2026-8619 Unauthenticated Denial-of-Service Vulnerability in HTTP Service in TP-Link TL-MR100, TL-MR150, TL-MR6400 and Archer MR600 Aug 19, 2026
  • CVE-2026-3841 Command Injection Vulnerability in Telnet CLI on TP-Link TL-MR6400 Mar 12, 2026

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No FIRST EPSS score.
  • No fixed version, patch or mitigation documented.
  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-12339 is "Authenticated Arbitrary File Write Vulnerability in multiple devices", rated Medium. It affects Archer MR200 v7 (TP-Link Systems Inc.); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 6.9 describes technical severity. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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