Remote denial of service via sleeping RCU teardown
Published Aug 26, 2026 · Updated Aug 27, 2026
Denial of service in the Linux kernel ovpn module 6.16 through 7.1.9 allows remote attackers to crash VPN gateway hosts. The key-slot kref release path calls crypto_free_aead from an RCU callback even though asynchronous or hardware AEAD teardown can sleep, violating atomic-context rules. An operational ovpn tunnel with peers and keys is required; a remote TCP disconnect or keepalive expiry can trigger an oops, RCU stall, or kernel panic.
Summary
What happened
Denial of service in the Linux kernel ovpn module 6.16 through 7.1.9 allows remote attackers to crash VPN gateway hosts. The key-slot kref release path calls crypto_free_aead from an RCU callback even though asynchronous or hardware AEAD teardown can sleep, violating atomic-context rules. An operational ovpn tunnel with peers and keys is required; a remote TCP disconnect or keepalive expiry can trigger an oops, RCU stall, or kernel panic.
The record
- CVE
- CVE-2026-74750
- Published
- Aug 26, 2026
- Updated
- Aug 27, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-663, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 26, 2026CVE publishedPublication date reported by the CVE source.
- Aug 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=6.16
- Affected versionversion=8534731dbf2d52a539b94defd06d2a8d3514aacb <0f77ed5ee91946ea63e29f2e0ff9dc9e722d8da3
- Affected versionversion=8534731dbf2d52a539b94defd06d2a8d3514aacb <2da3dfa1ddfe55a065f484750c83660e3bd4ac00
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
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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