Loading vulnerability…
CVE-2025-21963 is an integer overflow vulnerability in the Linux kernel CIFS/SMB client code when processing the acdirmax mount option. The user-supplied acdirmax parameter is a 32-bit unsigned value intended to be bounded, but the value is converted from seconds to jiffies before the upper-limit validation is performed. This ordering allows the conversion step itself to overflow, resulting in incorrect internal state derived from the mount option. The flaw affects the handling of CIFS mounts that accept this parameter and was fixed by correcting validation of the option during mount processing.
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.
1 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
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.