CVE-2026-97566

CVE CVE-2026-97566EUVD EUVD-2026-86874Published 2026-09-25T10:21:53.000Z

What the advisory describes

In the Linux kernel, the following vulnerability has been resolved: mptcp: pm: kernel: drop pending ADD_ADDR when removing ID0 The in-kernel MPTCP path manager can leave a stale ADD_ADDR announcement entry alive when removing the id 0 endpoint. This happens because the id 0 removal path does not tear down pending announcements, unlike the non-zero id path. When the PM later reselects id 0 after adding another signal endpoint, it finds the stale anno_list entry and hits WARN_ON_ONCE(mptcp_pm_is_kernel()) in mptcp_pm_announced_alloc(). Root cause: asymmetry between removal paths. - Non-zero id path: mptcp_nl_remove_subflow_and_signal_addr() calls mptcp_pm_remove_announced() to clean up. - Id 0 path: mptcp_nl_remove_id_zero_address() skips cleanup entirely. Fix by making the id 0 path symmetric: call mptcp_pm_announced_remove() and decrement add_addr_signaled before queuing the RM_ADDR. Subtle detail: signal endpoints are stored in anno_list with port 0, but msk_local carries the connection's local port. In other words, entries linked to ID0 paths should have port == 0. A follow-up patch will ensure that. mptcp_pm_announced_remove() uses use_port=true for comparison. So clear the port before the lookup.

Source: EUVD (ENISA), in the words of the advisory.

Products the advisory names

These come from the advisory itself, not from any check we performed.

Linux — Linux 5.13; 740d798e8767d8a449902b1a1bbc70facfce19b5 <2ac7d6e620764f1fc79eb4edd3610a7a661981ca; patch: 7.2.7; patch: 0; 740d798e8767d8a449902b1a1bbc70facfce19b5 <545616b4e7325be3c61fc082538cb06d14f7b1db; patch: 7.3-rc3; 740d798e8767d8a449902b1a1bbc70facfce19b5 <d4a67a880654e1bfe318a31bea0bdbb026a09ade; patch: 6.18.53

The versions shown are the advisory's own. Patchlage compares no version numbers and derives no judgement from them — which version is installed is something a person has to look up.

Carried in the product catalogue

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Linux — Linux

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