CVE-2026-121506: NTPsec · Out-of-bounds Write
Affects NTPsecSource CVE Database V5
Not known to be exploited · CVSS 7.4 High : upgrade to 1.2.5 soon.
Data as of 3 Nov 2026, 15:58 UTC
Thin evidence
One scorer or none| CNA (GitLab) | CVSS 3.1 | 7.4 |
|---|
- Patch
- Available – fixed in 1.2.5
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 3 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 3 Nov 2026.
What to do
Upgrade NTPsec and ntpsec/ntpsec to 1.2.5.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| NTPsecNTPsec | Affected
| Fixed in
|
GitHubntpsec/ntpsecpkg:github/ntpsec/ntpsecOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Upgrade NTPsec to version 1.2.5 or later, where this vulnerability is fixed. No other mitigation is required as the vendor has provided an official fix.
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.