Incus Allocation of Resources Without Limits allows firewall rule bypass on managed bridge networks

Exploitation

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

CVSS

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

EPSS

• CVE-2025-52889: 0.25% estimated exploitation activity in the next 30 days; percentile 16.96 (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 for local services (DHCP, DNS...) that partially bypass security options security.macfiltering, security.ipv4filtering and security.ipv6filtering. This can lead to DHCP pool exhaustion and opens the door for other attacks. Details In commit a7c33301738aede3c035063e973b1d885d9bac7c, the following rules are added at the top of the bridge input chain: iifname "{{.hostName}}" ether type ip ip saddr 0.0.0.0 ip daddr 255.255.255.255 udp dport 67 accept iifname "{{.hostName}}" ether type ip6 ip6 saddr fe80::/10 ip6 daddr ff02::1:2 udp dport 547 accept iifname "{{.hostName}}" ether type ip6 ip6 saddr fe80::/10 ip6 daddr ff02::2 icmpv6 type 133 accept However, these rules accept packets that should be filtered and maybe dropped by later rules in the "MAC filtering" snippet: iifname "{{.hostName}}" ether type arp arp saddr ether != {{.hwAddr}} drop iifname "{{.hostName}}" ether type ip6 icmpv6 type 136…

Published by the source

26 Jun 2025, 21:11 UTC

Last modified by the source

30 Mar 2026, 13:54 UTC

Source last checked

26 Oct 2026, 15:19 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-9q7c-qmhm-jv86

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# Patch Next advisory brief: CVE-2025-52889

Advisory: Incus Allocation of Resources Without Limits allows firewall rule bypass on managed bridge networks
IDs: CVE-2025-52889, GHSA-9q7c-qmhm-jv86
Record: https://patchnext.com/advisories/cve-2025-52889 (revision 1, source checked 26 Oct 2026, 15:19 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Low (CVSS 3.4)
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 <= 6.13.0; 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-9q7c-qmhm-jv86 (GitHub-reviewed advisory GHSA-9q7c-qmhm-jv86 lists affected ranges: Go github.com/lxc/incus/v6 >=0 <=6.13.0)

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