Memory Buffer Bounds ErrorWeakness · CWE-119

CVE-2026-19821

HIGH · 8.8 CVSS v3.1 Published 2026-08-14
No fix yet
No fix has been published. The vendor has not shipped a fixed release or patch. You remain exposed.
See remediation →
94/100
Remediation priority · Urgent
Remotely reachable Zero-click 5 days old

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
A vulnerability was determined in Tenda AC12 15.03.06.23_multi_TD01. This vulnerability affects the function formSetRebootTimer of the file /goform/SetSysAutoRebbotCfg of the component httpd web management interface. This manipulation of the argument rebootTime causes buffer overflow. The attack may be initiated remotely. The exploit has been publicly disclosed and may be utilized.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis
How this class of weakness works · CWE-119

The program reads or writes outside the bounds of an allocated buffer, corrupting adjacent memory. With crafted input an attacker can overwrite control data and, with effort, redirect execution to their own code. Remediation ranges from bounds checking and safe library functions to compiler mitigations, usually alongside a careful audit of the surrounding code.

General guidance for the memory buffer bounds error class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Recommended fix Low confidence
  1. 1. Contact Tenda official support directly to request a security firmware update for model AC12.
  2. 2. If no official patch is available, consider placing the device behind a firewall to limit remote attack surface.
  3. 3. Disable remote management interface access from WAN if not strictly necessary.
  4. 4. Monitor Tenda's support website (www.tenda.com.cn) for any firmware updates addressing this vulnerability.
  5. 5. Consider replacing the device if it reaches end-of-life and no security updates are provided.
Caveat Embedded devices like routers often have limited upgrade options and may reach end-of-life without security patches.

Generated from the published advisory — verify against the referenced sources before acting.

No vendor fix exists The vendor has not published a patch for this.

There is no version to upgrade to and no patch to apply. Every affected install stays exposed until the vendor ships a fix — or somebody else builds one.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-19821 in production — separate from our analysis above.

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What this is

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  • Version or environment caveats, and links to real fixes
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