Bug 2567334

Summary: CVE-2026-121506 ntpsec: ntpsec: Memory corruption via crafted NTS extension field [epel-all]
Product: [Fedora] Fedora EPEL Reporter: Oleg Sushchenko <osushche>
Component: ntpsecAssignee: Miroslav Lichvar <mlichvar>
Status: CLOSED RAWHIDE QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: epel10CC: geert, igor.raits, mlichvar
Target Milestone: ---Keywords: Security, SecurityTracking
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["4e17794f-3842-482f-925a-5a51fc0c32de"]}
Fixed In Version: Doc Type: ---
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2026-11-05 15:11:17 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On:    
Bug Blocks: 2565842    

Description Oleg Sushchenko 2026-11-05 15:02:06 UTC 
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

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.
Comment 1 Miroslav Lichvar 2026-11-05 15:11:17 UTC 
Fixed in
https://bodhi.fedoraproject.org/updates/FEDORA-EPEL-2026-077c9d1631
https://bodhi.fedoraproject.org/updates/FEDORA-EPEL-2026-1d3c013156