Local privilege escalation via unreferenced backing device
Published Feb 26, 2025 · Updated Aug 5, 2026
A use-after-free in the Linux kernel MACsec driver allows local users to escalate privileges by tearing down crafted network devices. macsec_dev_init stores real_dev without acquiring a reference, so deleting the lower veth can free it before macsec_get_iflink dereferences it during linkwatch processing. A user with access to user and network namespaces can reach the flaw through local rtnetlink operations, leading to kernel memory disclosure, arbitrary writes, control-flow hijacking, or a kernel panic.
Summary
What happened
A use-after-free in the Linux kernel MACsec driver allows local users to escalate privileges by tearing down crafted network devices. macsec_dev_init stores real_dev without acquiring a reference, so deleting the lower veth can free it before macsec_get_iflink dereferences it during linkwatch processing. A user with access to user and network namespaces can reach the flaw through local rtnetlink operations, leading to kernel memory disclosure, arbitrary writes, control-flow hijacking, or a kernel panic.
The record
- CVE
- CVE-2022-49390
- Published
- Feb 26, 2025
- Updated
- Aug 5, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-416, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Feb 26, 2025CVE publishedPublication date reported by the CVE source.
- Aug 5, 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=1861904a6092ed411203c6a02c75bfc45b27cc3c
- Affected versionversion=2bce1ebed17da54c65042ec2b962e3234bad5b47 <196a888ca6571deb344468e1d7138e3273206335
- Affected versionversion=2bce1ebed17da54c65042ec2b962e3234bad5b47 <78933cbc143b82d02330e00900d2fd08f2682f4e
- Affected versionversion=2bce1ebed17da54c65042ec2b962e3234bad5b47 <d130282179aa6051449ac8f8df1115769998a665
- Affected versionversion=3a2675a2d97a68332fa5c33043038bfeb31455a8
- Affected versionversion=4.14.154 <4.15
- Affected versionversion=4.19.84 <4.20
- Affected versionversion=5.3.11 <5.4
- Affected versionversion=5.4
- Affected versionversion=b0add6db3d5ec4561cab257358871a9d3df7f0a3
What conditions does exploitation require?
What is affected?
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.
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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