# CVE-2025-15356: Tenda AC20 PowerSaveSet sscanf buffer overflow

> Remote attackers can trigger a buffer overflow in the Tenda AC20 router's PowerSaveSet function, potentially leading to code execution or service disruption.

- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 30 Dec 2025
- **Updated:** 24 Feb 2026
- **Also known as:** GHSA-95cj-hx7q-rjj4

## What is CVE-2025-15356?

CVE-2025-15356 is a high-severity memory corruption vulnerability in Tenda AC20, published on 30 Dec 2025. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A vulnerability has been found in Tenda AC20 up to 16.03.08.12. The impacted element is the function sscanf of the file /goform/PowerSaveSet. The manipulation of the argument powerSavingEn/time/powerSaveDelay/ledCloseType leads to buffer overflow. The attack can be initiated remotely. The exploit has been disclosed to the public and may be used.

Weakness: CWE-120 (Buffer Copy without Checking Size of Input), CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2025-15356?

It affects 1 product.


Products: Tenda Ac20 Firmware.

## How do I fix CVE-2025-15356?

No fix has been published for CVE-2025-15356 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-15356 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-15356 exists.

## Other vulnerabilities in Tenda AC20

- [CVE-2025-14654](https://insights.sbomify.com/CVE-2025-14654/): Tenda AC20 httpd setPptpUserList formSetPPTPUserList stack-based overflow (high 8.7)
- [CVE-2025-14655](https://insights.sbomify.com/CVE-2025-14655/): Tenda AC20 httpd SetSysAutoRebbotCfg formSetRebootTimer stack-based overflow (high 8.7)
- [CVE-2025-14656](https://insights.sbomify.com/CVE-2025-14656/): Tenda AC20 openSchedWifi httpd buffer overflow (high 8.7)
- [CVE-2025-13258](https://insights.sbomify.com/CVE-2025-13258/): Tenda AC20 WifiExtraSet buffer overflow (high 8.7)
- [CVE-2025-11385](https://insights.sbomify.com/CVE-2025-11385/): Tenda AC20 fast_setting_wifi_set sscanf buffer overflow (high 8.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-15356 and fix it if it is affected.

What it is: CVE-2025-15356 is a high-severity memory corruption vulnerability in Tenda AC20, published on 30 Dec 2025. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-15356 exists.

Affected product: Tenda AC20. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2025-15356/ (Markdown: https://insights.sbomify.com/CVE-2025-15356/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-15356
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-15356
- OSV: https://osv.dev/vulnerability/CVE-2025-15356

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-15356/
Summaries are generated and may contain mistakes; the official description above is the record.