---
title: "CVE-2026-112816: Improper certificate validation in the HTTPS listener in LXD"
url: https://erroneo.us/security/cve/CVE-2026-112816/
description: "CVE-2026-112816 (Canonical LXD): Improper certificate validation in the HTTPS listener in Canonical LXD 4.0.14, 5.0.10, 5.21.8, 6.9 before 4.0.15, 5.0.11…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-10-30
date_modified: 2026-10-31
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-112816"
kev: false
cvss: 10
epss: 0.00303
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-112816: Improper certificate validation in the HTTPS listener in LXD

**Signal:** Critical and remotely reachable. No known exploitation yet, but it is network-reachable without credentials. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
- EPSS 0.3% , percentile 23: FIRST’s model estimates a 0.3% chance of exploitation activity in the next 30 days, higher than 23% of all scored CVEs (low). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Editorial verdict: Check exposure. LXD and MicroCloud mTLS Auth Bypass CVE-2026-112816 — Only LXD hosts with the HTTPS API enabled, which includes every cluster and MicroCloud, are at risk, but there the bug is a full authentication bypass to root, so refresh the snap this week.

## What it is

Improper certificate validation in the HTTPS listener in Canonical LXD 4.0.14, 5.0.10, 5.21.8, 6.9 before 4.0.15, 5.0.11, 5.21.9, 6.10.1 allows an unauthenticated attacker to authenticate as any trusted client and gain full access to the cluster and managed virtual machines via a crafted certificate chain.

## Affected products (CVE record)

- Canonical LXD: 4.0.14 < 4.0.15, 5.0.10 < 5.0.11, 5.21.8 < 5.21.9, 6.9.0 < 6.10.1

## Severity

- canonical CVSS 4.0: 10 `CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none , automatable yes , technical impact total .
- FIRST EPSS (model of 2026-11-05): 0.30% probability of exploitation activity in the next 30 days; percentile 23.

## Sources

- [github.com](https://github.com/canonical/lxd/security/advisories/GHSA-99jp-jwmc-65p4)
- [discourse.ubuntu.com](https://discourse.ubuntu.com/t/security-advisory-critical-vulnerability-found-in-canonical-lxd-and-microcloud/90557)
- [discourse.ubuntu.com](https://discourse.ubuntu.com/t/lxd-6-10-1-lts-has-been-released/90024)
- [discourse.ubuntu.com](https://discourse.ubuntu.com/t/lxd-5-21-9-lts-has-been-released/90565/1)
- [discourse.ubuntu.com](https://discourse.ubuntu.com/t/lxd-5-0-11-lts-has-been-released/90570/1)
- [discourse.ubuntu.com](https://discourse.ubuntu.com/t/lxd-4-0-15-lts-has-been-released/90571)
- [CVE.org record CVE-2026-112816](https://www.cve.org/CVERecord?id=CVE-2026-112816)
- [NVD entry CVE-2026-112816](https://nvd.nist.gov/vuln/detail/CVE-2026-112816)

---
Source page: https://erroneo.us/security/cve/CVE-2026-112816/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt