CVE-2026-12339

Administrator file overwrite via traversal archive entries

Published Aug 10, 2026 · Updated Aug 10, 2026

Path traversal in TP-Link 4G router firmware allows remote authenticated users to overwrite arbitrary files through ISP Upgrade archives. The WebUI extractor accepts archive member names containing directory traversal sequences and writes them outside its intended directory. Administrator privileges and adjacent network access are required; overwriting system files damages integrity and interrupts device operation.

CVSS severity6.9
Medium
EPSS probability0.34%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Path traversal in TP-Link 4G router firmware allows remote authenticated users to overwrite arbitrary files through ISP Upgrade archives. The WebUI extractor accepts archive member names containing directory traversal sequences and writes them outside its intended directory. Administrator privileges and adjacent network access are required; overwriting system files damages integrity and interrupts device operation.

The record

CVE
CVE-2026-12339
Published
Aug 10, 2026
Updated
Aug 10, 2026
Vendor
TP-Link Systems Inc.
Product
TL-MR6400
Classifications
CWE-22, T1565.001
Attack vector
adjacent
Privileges
admin

Timeline

How it unfolded

  1. Aug 10, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 10, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <(EU)_1.10.0 0.9.1 v0001.0 Build 260613 RC.76099n

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesadmin

What is affected?

TP-Link Systems Inc. · TL-MR6400version=0 <(EU)_1.10.0 0.9.1 v0001.0 Build 260613 RC.76099n
TP-Link Systems Inc. · Archer MR200version=0 <(EU)_1.3.0 0.9.1 v0001.0 Build 260605 Rel.57870n
TP-Link Systems Inc. · Archer MR600version=0 <(EU)_1.10.0 0.9.1 v0001.0 Build 260618 RC.40417n

Published CVSS scores

6.9TP-Link Systems Inc.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

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
T1565.001Stored Data Manipulation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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