# CVE-2025-12258: TOTOLINK A3300R POST Parameter cstecgi.cg setOpModeCfg stack-based overflow

> Remote attackers can trigger a stack-based buffer overflow in the TOTOLINK A3300R router via the opmode parameter, potentially leading to code execution.

- **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:X`)
- **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:** 27 Oct 2025
- **Updated:** 24 Feb 2026
- **Also known as:** GHSA-jxjv-q5pr-4jwv

## What is CVE-2025-12258?

CVE-2025-12258 is a high-severity memory corruption vulnerability in Totolink A3300r Firmware, published on 27 Oct 2025. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A vulnerability was detected in TOTOLINK A3300R 17.0.0cu.557_B20221024. Impacted is the function setOpModeCfg of the file /cgi-bin/cstecgi.cg of the component POST Parameter Handler. The manipulation of the argument opmode results in stack-based buffer overflow. The attack may be performed from remote.

Weakness: CWE-121 (Stack-based Buffer Overflow), CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2025-12258?

It affects 1 product.


Products: Totolink A3300r Firmware.

## How do I fix CVE-2025-12258?

No fix has been published for CVE-2025-12258 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-12258 being exploited?

There is no known exploitation of CVE-2025-12258 in the wild and no public exploit code.

## Other vulnerabilities in Totolink A3300r Firmware

- [CVE-2026-31175](https://insights.sbomify.com/CVE-2026-31175/): Command injection in n/a (critical 9.8)
- [CVE-2026-31177](https://insights.sbomify.com/CVE-2026-31177/): Command injection in n/a (critical 9.8)
- [CVE-2026-31178](https://insights.sbomify.com/CVE-2026-31178/): Command injection in n/a (critical 9.8)
- [CVE-2026-31181](https://insights.sbomify.com/CVE-2026-31181/): Command injection in n/a (critical 9.8)
- [CVE-2026-31170](https://insights.sbomify.com/CVE-2026-31170/): Command injection in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-12258 and fix it if it is affected.

What it is: CVE-2025-12258 is a high-severity memory corruption vulnerability in Totolink A3300r Firmware, published on 27 Oct 2025. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-12258 in the wild and no public exploit code.

Affected product: Totolink A3300r Firmware. 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-2025-12258/ (Markdown: https://insights.sbomify.com/CVE-2025-12258/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-12258
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-12258
- OSV: https://osv.dev/vulnerability/CVE-2025-12258

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-12258/
Summaries are generated and may contain mistakes; the official description above is the record.