⚠ Reference material — not professional advice. Test in staging, back up first, verify against your specific version. Use your own judgment for your environment.
● High · CVSS 7.1

How to Fix CVE-2026-0918: Critical Vulnerability in Tapo C220 v1

Other vulnerabilities in the same area that are worth patching alongside this one:

*By Sai Kiran Pandrala*

⚡ At a glance
SeverityCVSS 7.1 - High
Actively exploited?Not currently listed in CISA KEV
Affected0 < 1.4.2 Build 251112, 0 < 1.2.3 Build 251114, 0 < 1.4.3 Build 251128
Fixed inSee vendor advisory
Type (CWE)CWE-476: NULL Pointer Dereference

What is CVE-2026-0918?

CVE-2026-0918 is a security flaw in Tapo C220 v1. The Tapo C100 v5, C220 v1 and C520WS v2 cameras’ HTTP service does not safely handle POST requests containing an excessively large Content-Length header. The resulting failed memory allocation triggers a NULL pointer dereference, causing the main service process to crash.

Why this CVE matters

Unpatched network-facing software is the leading initial-access vector in public breach reporting. Treat any CVSS-9 class flaw on an internet-reachable system as urgent, regardless of whether public exploit code has been observed yet.

For deployments of Tapo C220 v1 that have been exposed to the public internet during the disclosure window, the operating assumption should be that scanning has already happened. Even where exploitation has not been publicly observed, scanning for the vulnerable fingerprint is cheap and routine. Patching closes the door; log review and credential rotation close out the rest of the response.

Am I affected?

You are affected if your installation matches any of these version ranges:

Check your installed version against the list above. If you cannot determine the version, treat the system as affected and follow the upgrade path below.

Open Tapo C220 v1's About dialog or run the vendor-documented version-check command. Compare the result against the affected ranges in the advisory.

How to fix CVE-2026-0918

The fix is to upgrade Tapo C220 v1 to one of these patched versions (pick the one matching your release line): 1.4.2 Build 251112, 1.2.3 Build 251114, 1.4.3 Build 251128.

Affected versions confirmed in the CVE record:

Apply the firmware update


<!-- enrich_agent_2:v1 -->
# Affected models + patched firmware (from the vendor advisory):
# - Tapo C220 v1: install firmware 1.4.2 Build 251112 or later
# - Tapo C520WS v2: install firmware 1.2.3 Build 251114 or later
# - Tapo C100 v5: install firmware 1.4.3 Build 251128 or later

# 1. Open the device's web admin UI on its LAN address.
#    (Most models default to http://192.168.1.1/ or http://routerlogin.net/.)
#    Sign in with the admin account.

# 2. Navigate to ADVANCED -> Administration -> Firmware Update (or "Router
#    Update"). Click Check. If the device offers an OTA, install it.

# 3. If no OTA is offered, download the patched .img / .chk firmware from the
#    vendor's product page (linked above) and upload it manually via
#    Administration -> Firmware Update -> Browse -> Upload.

# 4. Reboot when prompted, then re-confirm the running firmware version in
#    ADVANCED -> Administration -> Router Information.


<!-- enrich_agent_2:v1 -->
# Optional: pull the device-info page to confirm the running firmware version
# over the LAN (NETGEAR / generic example).
Invoke-WebRequest -Uri "http://routerlogin.net/RST_status.htm" -UseDefaultCredentials |
  Select-String -Pattern "Firmware Version"

Verify the fix worked


<!-- enrich_agent_2:v1 -->
# 1. Confirm the running version matches the fixed-in version from the advisory.
#    Cross-check against the vendor advisory: https://www.tp-link.com/us/support/faq/4923/

# 2. Re-scan with your vulnerability scanner. The scanner should no longer flag
#    this CVE on the patched host.
# Example with Nmap NSE:
nmap -sV --script vuln <target-host>

# 3. Inspect the service / kernel logs for crash-loops or rollback events in
#    the first hour after the upgrade.
journalctl -u <service-name> --since "1 hour ago"
dmesg --since "1 hour ago"

If you cannot patch immediately

No official workaround exists beyond restricting network exposure to the affected component. Apply the vendor patch as the primary remediation.

How to verify the fix worked

If your installation was internet-reachable during the disclosure window, treat log review as part of the remediation rather than an optional follow-up. Look for log entries that do not match your normal request patterns, especially repeated requests to the same uncommon endpoint, and any administrative changes you cannot tie back to a known operator.

Frequently asked questions

Is CVE-2026-0918 being exploited in the wild?

Public exploitation has not been confirmed by CISA at the time of writing. Treat the patch as time-sensitive anyway; reports often lag actual abuse.

Will a WAF or IDS rule fully mitigate CVE-2026-0918?

No. Network-layer filters can reduce noise and slow opportunistic scanners, but they will not stop a determined attacker. The vendor patch is the only durable fix.

How long should I plan for the upgrade?

Typical vendor-documented upgrade windows for Tapo C220 v1 run from a few minutes to under an hour depending on cluster size. Test in a staging environment first and follow the vendor's documented HA upgrade order.

References

*This guide was assembled from the official vendor advisory, the NVD record, and the CISA KEV catalog entry on 2026-05-25. Always confirm against the vendor advisory before applying changes in production.*