# CVE-2026-102483: NTPsec ntpd denial of service in NTS Cookie handling

Source: https://junglewise.ai/threats/cve-2026-102483-reachable-exit-in-ntpsec-ntpd-1-1-4-through-1-2-5-allows-a  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-21. Updated: 2026-10-21  
License: CC BY 4.0 with a link back

CVE-2026-102483 · Severity: high · CVSS 7.5 · Published 2026-10-21

NTPsec ntpd is a network time synchronization daemon. A remote attacker can crash the ntpd service by sending a specially crafted NTS (Network Time Security) request with excessive NTS Cookie Placeholder fields, causing the daemon to exit and disrupting time synchronization for systems relying on it.

Technologies: [Ntpsec Ntpd](https://junglewise.ai/threats/technologies/ntpsec-ntpd). Vendors: [Ntpsec](https://junglewise.ai/threats/vendors/ntpsec).

## Quick answers

**Is CVE-2026-102483 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-102483 being exploited in the wild.

**How severe is CVE-2026-102483?** High severity, with a CVSS score of 7.5, published 21 October 2026.

**Which products and versions are affected?** Ntpsec Ntpd 1.1.4 through 1.2.5.

**Is there a fix for CVE-2026-102483?** Yes: fixed in ntpd 1.2.6 or later (fix committed September 14, 2026). Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-102483 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-102483?** Check whether you run Ntpsec Ntpd 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 ntpd 1.2.6 or later (fix committed September 14, 2026)

## Technical details

The vulnerability is a reachable exit condition in NTPsec ntpd versions 1.1.4 through 1.2.5 in the NTS extension handling code. The flaw stems from two bugs: an incorrect length validation check for CookiePlaceholders that would accept zero-length placeholders, and the absence of a limit on the number of CookiePlaceholders processed, allowing an attacker to trigger an unhandled condition when the daemon attempts to send back more cookies than can fit in a response. A remote network attacker can exploit this without authentication by sending a crafted NTS request.

## Affected products

- NTPsec ntpd 1.1.4 through 1.2.5

## Timeline

- 2026-10-21: disclosed

## References

- [https://gitlab.com/NTPsec/ntpsec/-/commit/df83f3c4f](https://gitlab.com/NTPsec/ntpsec/-/commit/df83f3c4f)
- [https://gitlab.com/NTPsec/ntpsec/-/work_items/899](https://gitlab.com/NTPsec/ntpsec/-/work_items/899)

## Related threats

- [NTPsec ntpd out-of-bounds read in NTS extension parsing](https://junglewise.ai/threats/cve-2026-102486-out-of-bounds-read-in-nts-extension-field-parsing-in-ntpsec-ntpd)
- [NTPsec ntpd out-of-bounds read in Motorola Oncore driver](https://junglewise.ai/threats/cve-2026-102485-out-of-bounds-read-in-the-motorola-oncore-refclock-driver-in)
- [NTPsec ntpd heap buffer overflow in JJY refclock driver](https://junglewise.ai/threats/cve-2026-102484-heap-based-buffer-overflow-in-the-jjy-refclock-driver-in-ntpsec)