CVE-2026-121506 (GCVE-0-2026-121506)
Vulnerability from cvelistv5 – Published: 2026-11-03 14:17 – Updated: 2026-11-03 15:29
VLAI
EPSS
VEX
Title
Out-of-bounds Write in NTPsec
Summary
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.
Severity
7.4 (High)
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-11-03 15:15 UTC
CWE
- CWE-787 - Out-of-bounds Write
Assigner
References
Impacted products
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Browse all ATT&CK techniques and the vulnerabilities related to each.
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