Kernel memory corruption via PFCP netns use-after-free
Published Jan 31, 2025 · Updated Aug 5, 2026
Use-after-free in Linux kernel 6.10 through 6.12.10 allows local users to read and corrupt kernel memory through PFCP network namespaces. The pfcp_newlink function records a PFCP device in dev_net(dev) rather than the UDP socket's network namespace, leaving the socket tied to freed struct net storage when that namespace is deleted. An unprivileged local user can obtain namespace-scoped CAP_NET_ADMIN through unshare; the deterministic teardown sequence exposes read and write primitives and can crash the kernel.
Summary
What happened
Use-after-free in Linux kernel 6.10 through 6.12.10 allows local users to read and corrupt kernel memory through PFCP network namespaces. The pfcp_newlink function records a PFCP device in dev_net(dev) rather than the UDP socket's network namespace, leaving the socket tied to freed struct net storage when that namespace is deleted. An unprivileged local user can obtain namespace-scoped CAP_NET_ADMIN through unshare; the deterministic teardown sequence exposes read and write primitives and can crash the kernel.
The record
- CVE
- CVE-2025-21677
- Published
- Jan 31, 2025
- Updated
- Aug 5, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jan 31, 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
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=6.10
- Affected versionversion=76c8764ef36a5d37ea2e551bda28ac7f028383ba <1c35a66e2bfea53dea3562b2575ac7fd4c38ee61
- Affected versionversion=76c8764ef36a5d37ea2e551bda28ac7f028383ba <ffc90e9ca61b0f619326a1417ff32efd6cc71ed2
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.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
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