Security readout for executives and security teams
Plain-English summary
Incus versions before 7.3.0 allow a specifically permitted, non-admin user to turn limited image and instance access into root-level code execution on the host. Compromise could expose or disrupt every workload and secret trusted by that host.
Executive priority
Treat this as an emergency upgrade for affected multi-user or delegated-management hosts. Prioritize internet-reachable control planes and environments where tenants, developers, or automation hold both required permissions. Host-level compromise could invalidate isolation assumptions across multiple workloads.
Technical view
A crafted Incus image can make backup.yaml a symbolic link to a host file. When the root daemon writes the instance backup, it follows that link, enabling host-file modification and arbitrary root code execution. Exploitation requires an identity permitted to create both images and instances.
Likely exposure
Incus deployments below 7.3.0 are affected when non-admin TLS/RBAC identities can create images and instances. Risk is greatest where those permissions are delegated to untrusted users or automation. The supplied material does not establish how commonly this configuration is deployed.
Exploitation context
The CVSS 3.1 score is 9.9 because exploitation is network-accessible, low complexity, requires limited privileges, needs no user interaction, and crosses into the host security context. The bundle reports KEV as false, and the provided sources do not establish active exploitation.
Researcher notes
The issue maps to CWE-59 and CWE-61: improper link resolution and UNIX symbolic-link following. The decisive trust-boundary failure occurs when the privileged daemon writes through image-controlled backup.yaml. Public evidence supplied here confirms the flaw and patch boundary, but not exploitation in the wild.
Mitigation direction
- Upgrade affected Incus installations to version 7.3.0 or later.
- Until upgraded, revoke image or instance creation rights from untrusted non-admin identities.
- Restrict image imports and creation to trusted administrators or controlled automation.
- Review the vendor advisory for additional operational guidance before restoring delegated permissions.
Validation and detection
- Inventory Incus hosts and confirm every installed version is 7.3.0 or later.
- Identify TLS and RBAC identities permitted to create both images and instances.
- Review delegated permissions, project memberships, service accounts, and automation credentials.
- Investigate unexpected image creation, instance creation, or host-file changes on affected systems.
- Confirm restricted identities cannot regain both required permissions through inherited roles.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-59: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCWE-61: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupContainer behavior lookup
The affected technology mentions containers, so container-specific ATT&CK technique review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-63125 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Critical
- CVSS
- 9.9 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H3.16GitHub_MVulnerability scoring details
Base CVSS 3.1 score
9.9CriticalVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/lxc/incus/security/advisories/GHSA-6rqx-22hc-qm36CVE reference, GitHub_M · x_refsource_CONFIRM
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Link Resolution Before File Access
Improper Link Resolution Before File Access represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
UNIX Symbolic Link (Symlink) Following
UNIX Symbolic Link (Symlink) Following represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.