GHSA-453r-g2pg-cxxq · Severity: high · Ecosystem: go — Local Incus UI web server vulnerable to nuthentication bypass
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.
Conclusion & alert: CVE-2026-33898 is rated Low Risk (36.8/100): CVSS High severity, with low exploitation likelihood (EPSS 0.02%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-04-21 | 0.06% | 0.02% | -0.04% |
| 2 | 2026-03-27 | — | 0.06% | — |
Full EPSS history (2 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 8.8 | 3.1 | HIGH |
|
2.8 | 5.9 | [email protected] |
GHSA-453r-g2pg-cxxq · Severity: high · Ecosystem: go — Local Incus UI web server vulnerable to nuthentication bypass
| vendor | priority | summary | link |
|---|---|---|---|
debian
|
unimportant | CVE-2026-33898 unimportant priority: Debian including 1 source packages (incus), 3 status rows across 3 suites (forky, sid, trixie): resolved 2, open 1. | https://security-tracker.debian.org/tracker/CVE-2026-33898 |
redhat
|
high | — | https://access.redhat.com/security/cve/CVE-2026-33898 |
ubuntu
|
medium | CVE-2026-33898 medium priority: Ubuntu including 2 source packages (incus, lxd), 11 status rows across 7 suites (bionic, focal, jammy, noble, questing, upstream, xenial): DNE 4, needs-triage 4, not-affected 3. | https://ubuntu.com/security/CVE-2026-33898 |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| linuxcontainers | incus | < 6.23.0 | cpe:2.3:a:linuxcontainers:incus:*:*:*:*:*:*:*:* |
| URL | Tags |
|---|---|
| https://github.com/lxc/incus/security/advisories/GHSA-453r-g2pg-cxxq | Vendor Advisory |