Loading vulnerability…
CVE-2025-21795 is a Linux kernel NFSD flaw in NFSv4 callback shutdown handling. When an nfs4_client is in courtesy state, NFSD can unnecessarily issue a callback RPC. Because cl_cb_inflight remains nonzero, nfsd4_shutdown_callback hangs. The corrective change makes nfsd4_run_cb_work skip the callback RPC for clients in courtesy state.
Mallory correlates every CVE against your assets, your vendors, and active adversary campaigns. Know which vulnerabilities matter for you, not just which ones are loud.
What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.
What an attacker gets, and what they’ve been doing with it.
If you can’t patch tonight, do this now.
Patch, then assume compromise.
No public exploits tracked yet. Mallory keeps watching.
No public exploit code observed for this vulnerability.
Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.
Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.
7 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
Linux kernel NFSD shutdown-callback hang.
A Linux kernel NFSD availability flaw in which nfsd4_shutdown_callback can hang for roughly 15 minutes when an NFSv4 client is in courtesy state and callback work is attempted.
Linux kernel NFSD flaw involving a hang in nfsd4_shutdown_callback.
Linux kernel NFSD shutdown denial-of-service flaw.
Query your assets running an affected version, and investigate the blast radius.
Every observed campaign linking this CVE to a named adversary.
Malware families riding this exploit, with evidence and IOCs.
YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.
Cross-references every affected SKU, including bundled OEM variants.
Community discussion across Reddit, Mastodon, and other social sources.