CVE-2025-37864: In the Linux kernel, the following vulnerability has been resolved: net: dsa: clean up FDB, MDB, VLAN entries on unbind As explained in many places such as co

In the Linux kernel, the following vulnerability has been resolved: net: dsa: clean up FDB, MDB, VLAN entries on unbind As explained in many places such as co

In the Linux kernel, the following vulnerability has been resolved: net: dsa: clean up FDB, MDB, VLAN entries on unbind As explained in many places such as commit b117e1e8a86d ("net: dsa: delete dsa_legacy_fdb_add and dsa_legacy_fdb_del"), DSA is written given the assumption that higher layers have balanced additions/deletions. As such, it only makes sense to be extremely vocal when those assumptions are violated and the driver unbinds with entries still present. But Ido Schimmel points out a very simple situation where that is wrong: https://lore.kernel.org/netdev/ZDazSM5UsPPjQuKr@shredder/ (also briefly discussed by me in the aforementioned commit). Basically, while the bridge bypass operations are not something that DSA explicitly documents, and for the majority of DSA drivers this API simply causes them to go to promiscuous mode, that isn't the case for all drivers. Some have the necessary requirements for bridge bypass operations to do something useful - see dsa_switch_supports_uc_filtering(). Although in tools/testing/selftests/net/forwarding/local_termination.sh, we made an effort to popularize better mechanisms to manage address filters on DSA interfaces from user spac

Description from the National Vulnerability Database, published by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

What it means for a small business

Linux is on the computers, phones or browsers your team uses every day. Turn on automatic updates and restart: most of these fixes only take effect after a restart.

How likely is an attack? The Exploit Prediction Scoring System, run by FIRST (the global association of security response teams), puts the odds of this one being exploited in the next 30 days at 0.30%, higher than 22% of CVEs. That’s low, but low isn’t zero, and the odds jump the day someone publishes an exploit. Scored November 1, 2026, updated daily.

Check your own setup

Website check: reads what your site runs from the outside (WordPress version, plugins it can see, old server software) and matches it against this database.
Server check: what your web server says about itself, and whether that version has known flaws.

Sources

Part of the Huttenlocher Technologies vulnerability database, refreshed twice a day from CISA and the NVD. The title, category and plain-language guidance are ours; check the linked record before acting on a detail. This is general guidance, not a review of your systems.

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