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TI-2026-26256 Aliases CVE-2026-33898GHSA-453r-g2pg-cxxq

Local Incus UI web server vulnerable to nuthentication bypass

Priority MEDIUM 40CWE-287Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Required
Attack complexity
Low
Impact type
Security bypass
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-287.

Summary

Incus is a system container and virtual machine manager. Prior to version 6.23.0, the web server spawned by `incus webui` incorrectly validates the authentication token such that an invalid value will be accepted. `incus webui` runs a local web server on a random localhost port. For authentication, it provides the user with a URL containing an authentication token. When accessed with that token, Incus creates a cookie persisting that token without needing to include it in subsequent HTTP requests. While the Incus client correctly validates the value of the cookie, it does not correctly validate the token when passed int the URL. This allows for an attacker able to locate and talk to the temporary web server on localhost to have as much access to Incus as the user who ran `incus webui`. This can lead to privilege escalation by another local user or an access to the user's Incus instances and possibly system resources by a remote attack able to trick the local user into interacting with the Incus UI web server. Version 6.23.0 patches the issue.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00353 29th percentileScored 2026-11-07
Fix Fixed incus (lxc): 6.23.0github.com/lxc/incus/v6/cmd/incus (Go): 6.23.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
lxcincusbefore 6.23.06.23.0Patch availableCNA
—github.com/lxc/incus/v6/cmd/incus (Go)before 6.23.06.23.0Patch availableGHSA-453r-g2pg-cxxq
  • incus Vendorlxc Affected before 6.23.0 Fixed in 6.23.0 Patch available CNA
  • github.com/lxc/incus/v6/cmd/incus (Go) Vendor— Affected before 6.23.0 Fixed in 6.23.0 Patch available GHSA-453r-g2pg-cxxq

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:linuxcontainers:incus:*:*:*:*:*:*:*:*before 6.23.0Vulnerablelxc
  • cpe:2.3:a:linuxcontainers:incus:*:*:*:*:*:*:*:* Versions before 6.23.0 Vulnerable ·lxc

Remediation

  • Fix · CNA incus (lxc) Fixed in 6.23.0
  • Fix · GHSA-453r-g2pg-cxxq github.com/lxc/incus/v6/cmd/incus (Go) Fixed in 6.23.0 Advisory →

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product
  • Red Hat

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-33898
  2. 2026-10-03 Alias added: GHSA-453r-g2pg-cxxq

References

Advisory 2

Other 3

  • TI-2026-19296 Incus container image templating arbitrary host file read and write CVSS 3.1HIGH 8.7
  • TI-2026-19295 Incus container environment configuration newline injection CVSS 3.1HIGH 8.7
  • TI-2025-39899 Incus vulnerable to local privilege escalation through custom storage volumes CVSS 4.0HIGH 8.6
  • TI-2026-29045 Incus out-of-bounds panic in snapshot metadata handling allows denial of service CVSS 4.0HIGH 7.1
  • TI-2026-29009 Incus nil-pointer dereference in storage bucket import allows denial of service CVSS 4.0HIGH 7.1
  • TI-2026-26122 Incus vulnerable to denial of source through crafted bucket backup file CVSS 3.1MEDIUM 6.5
See all 17 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences