Incus creates nftables rules that partially bypass security options

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

8.1 · CVSS:3.1/AV:A/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:H

EPSS

• CVE-2025-52890: 0.23% estimated exploitation activity in the next 30 days; percentile 13.92 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary When using an ACL on a device connected to a bridge, Incus generates nftables rules that partially bypass security options security.macfiltering, security.ipv4filtering and security.ipv6filtering. This can lead to ARP spoofing on the bridge and to fully spoof another VM/container on the same bridge. Details In commit d137a063c2fe2a6983c995ba75c03731bee1557d, a few rules in the bridge input chain are moved to the top of the chain: ct state established,related accept iifname "{{.hostName}}" ether type arp accept iifname "{{.hostName}}" ip6 nexthdr ipv6-icmp icmpv6 type { nd-neighbor-solicit, nd-neighbor-advert } accept However, these rules accept packets that should be filtered and maybe dropped by later rules in the "MAC filtering", "IPv4 filtering" and "IPv6 filtering" snippets: iifname "{{.hostName}}" ether type arp arp saddr ether != {{.hwAddr}} drop iifname "{{.hostName}}" ether type ip6 icmpv6 type 136 @nh,528,48 != {{.hwAddrHex}} drop ... iifname "{{.hostName}}" ether…

Published by the source

26 Jun 2025, 21:12 UTC

Last modified by the source

26 Mar 2026, 02:27 UTC

Source last checked

26 Oct 2026, 15:18 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-p7fw-vjjm-2rwp

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# Patch Next advisory brief: CVE-2025-52890

Advisory: Incus creates nftables rules that partially bypass security options
IDs: CVE-2025-52890, GHSA-p7fw-vjjm-2rwp
Record: https://patchnext.com/advisories/cve-2025-52890 (revision 1, source checked 26 Oct 2026, 15:18 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/lxc/incus/v6 6.14.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/lxc/incus/v6: affected >= 6.12.0, <= 6.13.0; fixed in 6.14.0

## Suggested inspection (read-only)
- Go github.com/lxc/incus/v6: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/lxc/incus/v6.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-p7fw-vjjm-2rwp (GitHub-reviewed advisory GHSA-p7fw-vjjm-2rwp lists affected ranges: Go github.com/lxc/incus/v6 >=6.12.0 <=6.13.0)

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