CyberSecBulletin
CVE-2026-112816NVD status: Deferred

LXD: Improper Certificate Validation

Published Updated By the CyberSecBulletin desk

CVE-2026-112816 is a critical-severity improper certificate validation vulnerability in LXD from Canonical, with a CVSS 4.0 base score of 10.0 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 4.0.15, 5.0.11, 5.21.9 as the first without the flaw, so updating LXD to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.3% chance of exploitation within 30 days, which is low compared with other CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update LXD to 4.0.15 or 5.0.11 or 5.21.9 or 6.10.1, whichever matches your release line, or a later version.
  2. Read the advisory on discourse.ubuntu.com for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
CanonicalLXD4.0.14 up to, but not including, 4.0.15; 5.0.10 up to, but not including, 5.0.11; 5.21.8 up to, but not including, 5.21.9; 6.9.0 up to, but not including, 6.10.14.0.15, 5.0.11, 5.21.9, 6.10.1

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Attack requirements
NoneThe attack does not depend on a particular deployment or configuration.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Confidentiality (vulnerable system)
HighSerious loss of confidentiality on the vulnerable system.
Integrity (vulnerable system)
HighSerious loss of integrity on the vulnerable system.
Availability (vulnerable system)
HighSerious loss of availability on the vulnerable system.
Confidentiality (other systems)
HighSerious loss of confidentiality on systems beyond the vulnerable one.
Integrity (other systems)
HighSerious loss of integrity on systems beyond the vulnerable one.
Availability (other systems)
HighSerious loss of availability on systems beyond the vulnerable one.

Vector: 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. Scored by CNA (ubuntu.com).

Official description

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.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Certificate Validation

The product does not validate, or incorrectly validates, a certificate.

How developers prevent this class of flaw

  • Certificates should be carefully managed and checked to assure that data are encrypted with the intended owner's public key.
  • If certificate pinning is being used, ensure that all relevant properties of the certificate are fully validated before the certificate is pinned, including the hostname.

More Improper Certificate Validation vulnerabilities (CWE-295)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in LXD

All LXD vulnerabilities

Recent Improper Certificate Validation vulnerabilities

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