Local privilege escalation via incorrect AT_SECURE flag
Published Jun 27, 2026 · Updated Jun 27, 2026
Privilege escalation in FreeBSD allows local users to gain a set-ID Linux binary's privileges through the Linuxulator. The copyout_auxargs path checks P_SUGID before execve sets it, causing the Linuxulator to emit AT_SECURE as zero for a set-user-ID or set-group-ID binary. An unprivileged local account can consequently use LD_PRELOAD to inject a shared library that executes with the binary's elevated identity.
Summary
What happened
Privilege escalation in FreeBSD allows local users to gain a set-ID Linux binary's privileges through the Linuxulator. The copyout_auxargs path checks P_SUGID before execve sets it, causing the Linuxulator to emit AT_SECURE as zero for a set-user-ID or set-group-ID binary. An unprivileged local account can consequently use LD_PRELOAD to inject a shared library that executes with the binary's elevated identity.
The record
- CVE
- CVE-2026-49413
- Published
- Jun 27, 2026
- Updated
- Jun 27, 2026
- Vendor
- The FreeBSD Project
- Product
- FreeBSD
- Classifications
- CWE-266, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jun 27, 2026CVE publishedPublication date reported by the CVE source.
- Jun 27, 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
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Weakness, pattern, technique
Public exploit references
- ii4gsp CVE-2026-49413 FreeBSD LPEfunctional · demonstrated
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Technologies
Your stack
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Your stack
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