# CVE-2026-123664: NASA GCN Email Notification Handler authorization bypass

Source: https://junglewise.ai/threats/cve-2026-123664-a-security-flaw-has-been-discovered-in-nasa-gcn-gcn-nasa-gov-up  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-06. Updated: 2026-11-06  
License: CC BY 4.0 with a link back

CVE-2026-123664 · Severity: medium · CVSS 5.4 · Published 2026-11-06

NASA's General Coordinates Network (GCN) is a collaboration platform that distributes astronomy alerts to observatories and researchers worldwide. A flaw in its email notification system allows attackers to manipulate recipient addresses, bypassing authorization controls. An attacker could send notifications to unauthorized email addresses or modify email subscriptions remotely without proper permission.

Vendors: [Nasa](https://junglewise.ai/threats/vendors/nasa).

## Quick answers

**Is CVE-2026-123664 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-123664 being exploited in the wild.

**How severe is CVE-2026-123664?** Medium severity, with a CVSS score of 5.4, published 6 November 2026.

**Which products and versions are affected?** Nasa GCN up to b299b562af665878964b981a459f0a9c04b11adf (rolling release).

**Is there a fix for CVE-2026-123664?** Yes: fixed in <UNKNOWN>. Until then: Implement email verification for all email notification recipients before activation, as discussed in the project's issue tracking system. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-123664 attacked?** It is attacked over the network, in a web application.

**Am I affected by CVE-2026-123664?** Check whether you run Nasa GCN 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 <UNKNOWN>

Implement email verification for all email notification recipients before activation, as discussed in the project's issue tracking system.

## Technical details

An improper authorization vulnerability exists in the Email Notification Handler component at the /user/email endpoint. Manipulation of the Recipient argument allows an attacker to bypass authorization checks. The vulnerability is remotely exploitable and has been publicly disclosed; a fix is pending pull request approval.

## Affected products

- NASA GCN up to b299b562af665878964b981a459f0a9c04b11adf (rolling release)

## Timeline

- 2026-11-06: disclosed
- exploited: Public exploit released

## References

- [https://github.com/nasa-gcn/gcn.nasa.gov/](https://github.com/nasa-gcn/gcn.nasa.gov/)
- [https://github.com/nasa-gcn/gcn.nasa.gov/issues/3805](https://github.com/nasa-gcn/gcn.nasa.gov/issues/3805)