Loading vulnerability…
CVE-2025-37797 is a time-of-check/time-of-use use-after-free vulnerability in the Linux kernel net_sched Hierarchical Fair Service Curve (HFSC) queueing discipline, in hfsc_change_class(). The function initially checks that a child class queue is non-empty, then calls qdisc_peek_len(). For child qdiscs such as CoDel or netem, that call can drop packets and empty the queue. The vulnerable code can nevertheless insert the now-empty HFSC class into the virtual-time tree (vttree), violating the scheduler invariant that vttree contains only non-empty classes. Subsequent class destruction can leave the tree referencing freed class memory, resulting in a use-after-free. The upstream fix revalidates the queue length after qdisc_peek_len() before adding the class to vttree.
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.
28 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
A ChromeOS LTS-138 security fix referenced in the release notes; the specific vulnerability details are not provided in the content.
Use-after-free flaw in Linux kernel HFSC traffic scheduling class handling.
A use-after-free vulnerability in Linux kernel net_sched HFSC class handling.
Use-after-free vulnerability in Linux kernel net_sched HFSC class handling.
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.