# Authenticated Arbitrary File Write Vulnerability in multiple devices

CVE record · `CVE-2026-12339`

- **Identifiers:** `CVE-2026-12339`
- **State:** Confirmed
- **Severity:** CVSS 6.9 Medium
- **Critical:** No
- **CNA:** TPLink
- **Weakness (CWE):** [CWE-22](https://cwe.mitre.org/data/definitions/22.html)
- **Tags:** [Path traversal](https://agentprime.io/advisories/tag/path-traversal.md)
- **Technologies:** [TP-Link Systems Inc. TL-MR6400 v5.3](https://agentprime.io/advisories/technology/tp-link-systems-inc-tl-mr6400-v5-3.md) · [TP-Link Systems Inc. Archer MR600 v2](https://agentprime.io/advisories/technology/tp-link-systems-inc-archer-mr600-v2.md) · [TP-Link Systems Inc. Archer MR200 v7](https://agentprime.io/advisories/technology/tp-link-systems-inc-archer-mr200-v7.md) · [TP-Link Systems Inc. TL-MR6400 v8.0](https://agentprime.io/advisories/technology/tp-link-systems-inc-tl-mr6400-v8-0.md) · [TP-Link Systems Inc. TL-MR150 v3.20](https://agentprime.io/advisories/technology/tp-link-systems-inc-tl-mr150-v3-20.md) · [TP-Link Systems Inc. TL-MR100 v3.20](https://agentprime.io/advisories/technology/tp-link-systems-inc-tl-mr100-v3-20.md)
- **Published:** 10 Aug 2026
- **Updated:** 25 Aug 2026
- **Reviewed by a person:** No

Published by the CVE Program (CNA: TPLink) at 10 Aug 2026, 18:20 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it.

## Affected products, as the CNA wrote them

- Vendor: TP-Link Systems Inc.. Product: TL-MR6400 v5.3.
  - affected: `before (EU)_1.10.0 0.9.1 v0001.0 Build 260613 RC.76099n` (custom)
  - Other versions: unaffected
- Vendor: TP-Link Systems Inc.. Product: Archer MR600 v2.
  - affected: `before (EU)_1.10.0 0.9.1 v0001.0 Build 260618 RC.40417n` (custom)
  - Other versions: unaffected
- Vendor: TP-Link Systems Inc.. Product: Archer MR200 v7.
  - affected: `before (EU)_1.3.0 0.9.1 v0001.0 Build 260605 Rel.57870n` (custom)
  - Other versions: unaffected
- Vendor: TP-Link Systems Inc.. Product: TL-MR6400 v8.0.
  - affected: `before (EU)_1.5.0 0.9.1 v0001.0 Build 260610 Rel.67978n` (custom)
  - Other versions: unaffected
- Vendor: TP-Link Systems Inc.. Product: TL-MR150 v3.20.
  - affected: `before (EU)_1.3.0 0.9.1 v0001.0 Build 260720 Rel.59727n` (custom)
  - Other versions: unaffected
- Vendor: TP-Link Systems Inc.. Product: TL-MR100 v3.20.
  - affected: `before (EU)_1.3.0 0.9.1 v0001.0 Build 260609 Rel.49957n` (custom)
  - affected: `before 1.1.0 0.9.1 v0001.0 Build 260609 Rel35479n, Customized Software for South Korea KT` (custom)
  - affected: `before 1.2.0 0.9.1 v0001.0 Build 260609 Rel.36250n, Customized Software for South Korea Telenor` (custom)
  - Other versions: unaffected

## Not analysed yet

We haven’t published our own analysis of this CVE. If a person reviews it, this page will say what’s affected and what has to be true for it to matter.

## Severity and exploitation

- 6.9 Medium, CVSS 4.0: `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`, from CNA (TPLink)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0053, the 45th percentile, on 14 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

This record came from the full history of the CVE Program, published 10 Aug 2026. New records show when each source confirmed them.

## Sources

- [CVE List: CVE-2026-12339](https://www.cve.org/CVERecord?id=CVE-2026-12339)
- [NVD: CVE-2026-12339](https://nvd.nist.gov/vuln/detail/CVE-2026-12339)

### References from the CNA

- <https://www.tp-link.com/en/support/download/tl-mr6400/v5.30/#Firmware> (patch)
- <https://www.tp-link.com/en/support/download/archer-mr600/v2/#Firmware> (patch)
- <https://www.tp-link.com/en/support/download/archer-mr200/v7/#Firmware> (patch)
- <https://www.tp-link.com/en/support/faq/5237/> (vendor-advisory)
- <https://www.tp-link.com/en/support/download/tl-mr100/v3.20/#Firmware> (patch)
- <https://www.tp-link.com/en/support/download/tl-mr150/v3.20/#Firmware> (patch)
- <https://www.tp-link.com/en/support/download/tl-mr6400/v8/#Firmware> (patch)
- <https://www.tp-link.com/kr/support/download/tl-mr100/v3.20/#Firmware> (patch)

Facts on this page come from the CVE List as the CNA published them, with CVSS from the sources named above, CISA KEV and FIRST EPSS. Vendors, products and versions are shown as the CNA wrote them. We don’t reproduce the CVE’s description.

## Check whether this affects you

This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it. Compare the affected versions above with what you run.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), `get_advisory` returns this record and `search_advisories` finds related ones. Setup: <https://agentprime.io/mcp.md>
- As JSON: <https://api.agentprime.io/v1/advisories/CVE-2026-12339>
- Everything that needs attention now: <https://agentprime.io/advisories/critical.md>

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The web page: <https://agentprime.io/advisories/CVE-2026-12339/>. Everything for agents: <https://agentprime.io/llms.txt>.