4.8

CVE-2026-97566: linux

CVSS: 4.8v4.0MediumReceived
AliasesUBUNTU-CVE-2026-97566DEBIAN-CVE-2026-97566
Published 25-09-2026Last modified 21-10-2026
Open JSON

Vulnerability summary

CVE-2026-97566 is a medium (CVSS 4.8) vulnerability in linux. EPSS estimates a 0.20% chance of exploitation in the next 30 days, higher than 9.3% of scored vulnerabilities.

Overall risk
19/100
0100
Low · default modelHow is this calculated?
CVSS score
4.8/10
010
Medium · v4.0 (OSV · Ubuntu), selected by version preference
EPSS score
0.20%
0%100%
Low · Change unavailable
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 1 · Related 1
OPENSUSE-SU-2026:12074-1

Timeline

  1. 25-09-2026
    PublishedVulnerability first disclosed.
  2. 21-10-2026
    Last modifiedVulnerability information updated.

Description

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.

CVSS metrics

1 score · 1 source · 1 version

EPSS trend

Probability

0.20%

Chance of exploitation in the next 30 days

Percentile

9%

Versus all other CVEs

30-day change

Change unavailable

Change unavailable

26-09-202621-10-2026
EPSS score
0.20%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

No weakness data has been published for this record.

Affected systems

Ubuntu157 products
  • linuxAll versions (No fix recorded)
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded)
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Debian1 product
  • linuxAll versions (No fix recorded) | < 6.12.113-1 | < 7.2.7-1
Linux1 product
  • linux≥ 740d798e8767d8a449902b1a1bbc70facfce19b5, < 189d60057e5f3d6a62e3d71a3cc428c9150bc14f | ≥ 740d798e8767d8a449902b1a1bbc70facfce19b5, < bacf23e7c9876c9f4170166b3597cb22ea3ed39b | ≥ 740d798e8767d8a449902b1a1bbc70facfce19b5, < d4a67a880654e1bfe318a31bea0bdbb026a09ade | ≥ 740d798e8767d8a449902b1a1bbc70facfce19b5, < 545616b4e7325be3c61fc082538cb06d14f7b1db | ≥ 740d798e8767d8a449902b1a1bbc70facfce19b5, < 2ac7d6e620764f1fc79eb4edd3610a7a661981ca | 5.13

3 vendors · 159 products

References

8 links