Namespace teardown hang via retained fragment queues
Published Jan 13, 2026 · Updated Jan 13, 2026
A deadlock in Linux Kernel allows attackers to hang network namespace teardown through stale IPv4 or IPv6 fragment-queue references. The fqdir_pre_exit() path leaves fragment-queue SKBs holding conntrack references because nf_defrag_ipv6 exit hooks run after conntrack cleanup. The hang requires conntrack, IPv6 defragmentation, pending fragmented packets, and network-namespace teardown; the reported consequence is an indefinitely spinning cleanup path.
Summary
What happened
A deadlock in Linux Kernel allows attackers to hang network namespace teardown through stale IPv4 or IPv6 fragment-queue references. The fqdir_pre_exit() path leaves fragment-queue SKBs holding conntrack references because nf_defrag_ipv6 exit hooks run after conntrack cleanup. The hang requires conntrack, IPv6 defragmentation, pending fragmented packets, and network-namespace teardown; the reported consequence is an indefinitely spinning cleanup path.
The record
- CVE
- CVE-2025-68768
- Published
- Jan 13, 2026
- Updated
- Jan 13, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- Unavailable
- Attack vector
- Unavailable
- Privileges
- Unavailable
Timeline
How it unfolded
- Jan 13, 2026CVE publishedPublication date reported by the CVE source.
- Jan 13, 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=5.3
- Affected versionversion=d5dd88794a13c2f24cce31abad7a0a6c5e0ed2db <006a5035b495dec008805df249f92c22c89c3d2e
- Affected versionversion=d5dd88794a13c2f24cce31abad7a0a6c5e0ed2db <c70df25214ac9b32b53e18e6ae3b8f073ffa6903
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
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
No sourced classifications are available.
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