CVE-2026-121505

Name	CVE-2026-121505
Description	An out-of-bounds read in the NTS-KE client response parser (nts_client_process_response_core) in NTPsec before 1.2.4 allows a malicious NTS-KE server to read the client's stack memory, including pointers that defeat ASLR, which the client then sends in cleartext as NTS cookies, via an NTS-KE record whose declared length exceeds the data received.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
ntpsec (PTS)	bookworm, bookworm (security)	1.2.2+dfsg1-1+deb12u1	vulnerable
	trixie	1.2.3+dfsg1-8	vulnerable
	forky, sid	1.2.5+dfsg-1	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
ntpsec	source	(unstable)	1.2.4+dfsg-1

Notes

https://gitlab.com/NTPsec/ntpsec/-/commit/caf0eb5df3c6ddbfc2941389bff0f9146835c021 (NTPsec_1_2_4)
https://gitlab.com/NTPsec/ntpsec/-/work_items/836
https://gitlab.com/NTPsec/ntpsec/-/work_items/902