Local privilege escalation via zero-SPI state retention
Published Oct 13, 2025 · Updated Aug 5, 2026
Use-after-free in the Linux kernel XFRM subsystem allows local users to escalate privileges through a zero-valued SPI allocation. xfrm_alloc_spi accepts SPI 0 and inserts the resulting state into the by-SPI list, while __xfrm_state_delete frees it without removing that list entry. Exploitation requires local access and CAP_NET_ADMIN in a network namespace; traversing the dangling entry enables privilege escalation or a kernel crash.
Summary
What happened
Use-after-free in the Linux kernel XFRM subsystem allows local users to escalate privileges through a zero-valued SPI allocation. xfrm_alloc_spi accepts SPI 0 and inserts the resulting state into the by-SPI list, while __xfrm_state_delete frees it without removing that list entry. Exploitation requires local access and CAP_NET_ADMIN in a network namespace; traversing the dangling entry enables privilege escalation or a kernel crash.
The record
- CVE
- CVE-2025-39965
- Published
- Oct 13, 2025
- Updated
- Aug 5, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Oct 13, 2025CVE publishedPublication date reported by the CVE source.
- Oct 31, 2025Exploitation reportedKernelCTF root exploitation
- Aug 5, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=29e9158f91f99057dbd35db5e8674d93b38549fe <a78e55776522373c446f18d5002a8de4b09e6bf7
- Affected versionversion=2fc5b54368a1bf1d2d74b4d3b8eea5309a653e38 <9fcedabaae0096f712bbb4ccca6a8538af1cd1c8
- Affected versionversion=3d8090bb53424432fa788fe9a49e8ceca74f0544 <0baf92d0b1590b903c1f4ead75e61715e50e8146
- Affected versionversion=6.12.43 <6.12.50
- Affected versionversion=6.15.11 <6.16
- Affected versionversion=6.16.2 <6.16.10
- Affected versionversion=6.6.103 <6.6.109
- Affected versionversion=94f39804d891cffe4ce17737d295f3b195bc7299 <cd8ae32e4e4652db55bce6b9c79267d8946765a9
- Affected versionversion=c67d4e7a8f90fb6361ca89d4d5c9a28f4e935e47
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
- CVE-2025-39965 XFRM trigger PoCfunctional · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Reported exploitation
- KernelCTF root exploitationreported exploitation
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo