In the Linux kernel, the following vulnerability has been resolved: net: bridge: stop fast-leave after deleting a port group br_multica…
CVE-2026-74480 · published 15 Aug 2026
How serious is it
- Severity: critical, CVSS score 9.8 out of 10.
- No exploit prediction (EPSS) score yet.
- Not on the CISA list of exploited vulnerabilities.
- No public exploit in Exploit-DB.
Is your app affected by CVE-2026-74480?
Paste this prompt into Claude Code, Cursor or any AI coding tool: it runs a free Shippable scan of your project and fixes what it finds. Built with Lovable, Bolt or v0? Scan your live app. Or upload your package file.
Who is affected
- Linux Linux: 4.11
How to check
- Find out whether you run the affected product and which version, then compare it with the versions above.
How to fix
Copies a prompt for Claude Code, Cursor or Codex that asks it to check whether you run this product.
- Apply the vendor's update or mitigation from the references below. If there is none yet, limit exposure of the affected service until there is.
- If a vulnerable version was live, check your logs and rotate the secrets that server could read.
The advisory
In the Linux kernel, the following vulnerability has been resolved:
net: bridge: stop fast-leave after deleting a port group
br_multicast_leave_group() iterates mp->ports with pp = &p->next in
its fast-leave path. After br_multicast_del_pg() removes p,
continuing the loop advances pp through the deleted entry.
If multicast-to-unicast was enabled, the bridge can hold multiple port
groups for the same port and group with different source MAC
addresses. Once multicast-to-unicast is disabled,
br_port_group_equal() matches those entries by port only. A fast leave
can then delete one entry and continue from its stale next pointer,
leaving mp->ports pointing at a deleted port group.
Fast leave only needs to remove one matching port group. Break after
br_multicast_del_pg() so the loop stops before dereferencing the
removed entry.
Check your whole app
Dependencies are only half of it. Free and read-only: before you push, run npx shippable-dev scan localhost:3000 in your project folder, no account needed. For your live app, you prove it's yours with a one-line tag first.
References
- git.kernel.org/stable/c/0309ebbc570000ea0df11c06b69798e5860c5f6f
- git.kernel.org/stable/c/159ad90cb929c033308bb39a2c5f8fbf393b77aa
- git.kernel.org/stable/c/1a109cc9890d017c41d77e6c82da739579c49f0b
- git.kernel.org/stable/c/4695430e8132420bf8de94da3eb36a6cf35fde6b
- git.kernel.org/stable/c/482bcb85139addb4e8ac8ed10baeda3e0aad4031
- git.kernel.org/stable/c/4c57056ca6aace2e9f94ae9298bf49ef6b0c95e4
- git.kernel.org/stable/c/a39789f211b8a4125f0c70e05b30cf715f4f187d
- git.kernel.org/stable/c/d6c32e2e25a9a06ba021030e26b6d602a277eb72
Merged from NVD. Last updated 24 Oct 2026. All vulnerabilities · RSS · JSON