An out-of-bounds read and write in NTS client extension field parsing (extens_client_recv) in NTPsec before 1.2.5 allows a remote attacker who can send NTP server-mode replies to an NTS client to corrupt heap memory and crash ntpd, and, combined with the NTS-KE client out-of-bounds read fixed in 1.2.4, to bypass NTS authentication and set the client's time, via an NTS Authenticator and Encrypted Extension Fields field whose nonce length exceeds the field.
Advisories

No advisories yet.

Fixes

Solution

Upgrade to version 1.2.5 or above.


Workaround

No workaround given by the vendor.

History

Tue, 03 Nov 2026 16:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Tue, 03 Nov 2026 14:30:00 +0000

Type Values Removed Values Added
Description An out-of-bounds read and write in NTS client extension field parsing (extens_client_recv) in NTPsec before 1.2.5 allows a remote attacker who can send NTP server-mode replies to an NTS client to corrupt heap memory and crash ntpd, and, combined with the NTS-KE client out-of-bounds read fixed in 1.2.4, to bypass NTS authentication and set the client's time, via an NTS Authenticator and Encrypted Extension Fields field whose nonce length exceeds the field.
Title Out-of-bounds Write in NTPsec
Weaknesses CWE-787
References
Metrics cvssV3_1

{'score': 7.4, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitLab

Published:

Updated: 2026-11-03T15:29:28.236Z

Reserved: 2026-11-03T14:17:04.662Z

Link: CVE-2026-121506

cve-icon Vulnrichment

Updated: 2026-11-03T15:29:25.361Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-11-03T15:17:37.717

Modified: 2026-11-03T16:17:24.840

Link: CVE-2026-121506

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses