# CVE-2026-1425: pymumu SmartDNS SVBC Record dns.c _dns_decode_SVCB_HTTPS stack-based overflow

> Remote attackers can trigger a stack-based buffer overflow in SmartDNS via crafted SVBC records, potentially leading to code execution or service disruption.

- **Severity:** Medium 6.3 (`CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:X`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 26 Jan 2026
- **Updated:** 23 Feb 2026
- **Also known as:** DEBIAN-CVE-2026-1425, GHSA-hqj6-7698-rxx4, UBUNTU-CVE-2026-1425

## What is CVE-2026-1425?

CVE-2026-1425 is a medium-severity memory corruption vulnerability in pymumu SmartDNS, published on 26 Jan 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A security flaw has been discovered in pymumu SmartDNS up to 47.1. This vulnerability affects the function _dns_decode_rr_head/_dns_decode_SVCB_HTTPS of the file src/dns.c of the component SVBC Record Parser. The manipulation results in stack-based buffer overflow. It is possible to launch the attack remotely. A high complexity level is associated with this attack. It is stated that the exploitability is difficult. The patch is identified as 2d57c4b4e1add9b4537aeb403f794a084727e1c8. Applying a patch is advised to resolve this issue.

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-2026-1425?


## How do I fix CVE-2026-1425?

Apply the vendor's patch.

## Is CVE-2026-1425 being exploited?

There is no known exploitation of CVE-2026-1425 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-1425 and fix it if it is affected.

What it is: CVE-2026-1425 is a medium-severity memory corruption vulnerability in pymumu SmartDNS, published on 26 Jan 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-1425 in the wild and no public exploit code.

Affected product: pymumu SmartDNS. 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-2026-1425/ (Markdown: https://insights.sbomify.com/CVE-2026-1425/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-1425
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-1425
- OSV: https://osv.dev/vulnerability/CVE-2026-1425

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-1425/
Summaries are generated and may contain mistakes; the official description above is the record.