CVE-2026-55707

high

Description

In OpenStack Neutron before 28.0.2, the subnetpool onboarding API does not verify ownership of the target subnets. An authenticated user can onboard subnets from another project's shared network into their own subnetpool, mutating the victim's subnet state and altering L3 routing and address scope behavior for victim routers.

References

Advisories
More

https://www.openwall.com/lists/oss-security/2026/07/29/5

https://security.openstack.org/ossa/OSSA-2026-032.html

https://lists.debian.org/debian-lts-announce/2026/08/msg00024.html

https://launchpad.net/bugs/2152113

http://www.openwall.com/lists/oss-security/2026/07/29/5

Details

Source: Mitre, NVD

Published: 2026-08-05

Updated: 2026-08-12

Risk Information

CVSS v2

Base Score: 7.5

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P

Severity: High

CVSS v3

Base Score: 9.8

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Severity: Critical

CVSS v4

Base Score: 7.1

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N

Severity: High

EPSS

EPSS: 0.00487