Local privilege escalation via in-place KTLS decryption
Published Jun 26, 2026 · Updated Jun 26, 2026
Write-what-where in affected FreeBSD KTLS releases allows local users to overwrite readable files and escalate privileges. The receive path decrypts sendfile(2)-originated M_EXTPG or EXT_SFBUF mbufs in place, so attacker-chosen plaintext replaces file-backed page-cache data instead of a private buffer. An unprivileged local user needs read access to the target and a loopback socket with KTLS receive enabled; overwriting a setuid binary grants root-level control.
Summary
What happened
Write-what-where in affected FreeBSD KTLS releases allows local users to overwrite readable files and escalate privileges. The receive path decrypts sendfile(2)-originated M_EXTPG or EXT_SFBUF mbufs in place, so attacker-chosen plaintext replaces file-backed page-cache data instead of a private buffer. An unprivileged local user needs read access to the target and a loopback socket with KTLS receive enabled; overwriting a setuid binary grants root-level control.
The record
- CVE
- CVE-2026-45257
- Published
- Jun 26, 2026
- Updated
- Jun 26, 2026
- Vendor
- The FreeBSD Project
- Product
- FreeBSD
- Classifications
- CWE-123, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jun 26, 2026CVE publishedPublication date reported by the CVE source.
- Jun 26, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=14.3-RELEASE <p15
- Affected versionversion=14.4-RELEASE <p6
- Affected versionversion=15.0-RELEASE <p10
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- bumsrakete.cfunctional · demonstrated
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Technologies
Your stack
See the directory against your own environment.
Your stack
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