# CVE-2026-72752: NLnet Labs Routinator denial of service via repeated JSON requests

Source: https://junglewise.ai/threats/cve-2026-72752-routinator-runs-out-of-memory-when-the-json-output-is-requested  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-26. Updated: 2026-10-26  
License: CC BY 4.0 with a link back

CVE-2026-72752 · Severity: medium · CVSS 6.5 · Published 2026-10-26

Routinator is an open-source RPKI (Route Origin Authorization) validator used by network operators to secure BGP routing. An attacker can crash Routinator and cause a denial of service by opening many concurrent connections to request JSON output, or by sending specially crafted payloads with excessive metadata, leading to memory exhaustion or stack overflow.

Technologies: [NLnet Labs Routinator](https://junglewise.ai/threats/technologies/routinator). Vendors: [NLnet Labs](https://junglewise.ai/threats/vendors/nlnet-labs).

## Quick answers

**Is CVE-2026-72752 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-72752 being exploited in the wild.

**How severe is CVE-2026-72752?** Medium severity, with a CVSS score of 6.5, published 26 October 2026.

**Which products and versions are affected?** NLnet Labs Routinator up to and including 0.15.2.

**Is there a fix for CVE-2026-72752?** Yes: fixed in Routinator 0.15.3 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-72752 attacked?** It is attacked over the network, in a hosted service.

**Am I affected by CVE-2026-72752?** Check whether you run NLnet Labs Routinator at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in Routinator 0.15.3 or later

## Technical details

Routinator exhibits two denial-of-service conditions: memory exhaustion when JSON output is requested many times concurrently, and stack overflow when processing payload items with excessive metadata. Both can be triggered remotely via the HTTP server if exposed to untrusted networks. The vulnerabilities do not require authentication and result in application crash and service unavailability.

## Affected products

- NLnet Labs Routinator up to and including 0.15.2

## Timeline

- 2026-10-26: disclosed

## References

- [https://www.nlnetlabs.nl/downloads/routinator/CVE-2026-72752.txt](https://www.nlnetlabs.nl/downloads/routinator/CVE-2026-72752.txt)

## Related threats

- [Routinator AS range parsing memory exhaustion](https://junglewise.ai/threats/cve-2026-72758-when-parsing-an-as-range-in-routinator-if-the-maximum-value-of)
- [Routinator HTTP server denial of service via resource exhaustion](https://junglewise.ai/threats/cve-2026-72757-routinator-runs-out-of-open-connections-on-the-http-server-when)
- [Routinator denial of service from malformed rsync URIs](https://junglewise.ai/threats/cve-2026-72756-routinator-exits-when-an-rsync-uri-for-a-file-obtained-over-rrdp)
- [Routinator CRL parsing denial of service](https://junglewise.ai/threats/cve-2026-72754-when-routinator-encounters-a-crl-with-many-entries-it-may-hang-or)
- [Routinator improper RRDP delta entry validation](https://junglewise.ai/threats/cve-2026-72753-when-routinator-encounters-an-rrdp-notification-file-with-gaps-in)