CVE-2026-63343
Arbitrary File Read/Write: metadata.yaml symlink in image allows host filesystem access as root
Incus is a system container and virtual machine manager. Prior to version 7.3.0, a malicious image containing a metadata.yaml symlink pointing to an arbitrary host path allows an authenticated Incus user to read or overwrite any file on the host as root via the instance metadata API. The exec-output and templates/ paths were patched in a prior release using Lstat rejection and os.OpenRoot confinement; metadata.yaml was not included in either patch and remains exploitable. Version 7.3.0 patches the issue.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
9.9
Arbitrary File Read/Write: metadata.yaml symlink in image allows host filesystem access as root
Incus is a system container and virtual machine manager. Prior to version 7.3.0, a malicious image containing a metadata.yaml symlink pointing to an arbitrary host path allows an authenticated Incus user to read or overwrite any file on the host as root via the instance metadata API. The exec-output and templates/ paths were patched in a prior release using Lstat rejection and os.OpenRoot confinement; metadata.yaml was not included in either patch and remains exploitable. Version 7.3.0 patches the issue.
- Record
CVE-2026-63343- CVSS 3.1
- 9.9 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H - Weakness
- CWE-73
- Updated
- 2026-11-02
EUVDEUVD-2026-63989
9.9
Incus is a system container and virtual machine manager. Prior to version 7.3.0, a malicious image containing a metadata.yaml symlink pointing to an arbitrary host path allows an authenticated Incus user to read or overwrite any file on the host as root via the instance metadata API. The exec-output and templates/ paths were patched in a prior release using Lstat rejection and os.OpenRoot confinement; metadata.yaml was not included in either patch and remains exploitable. Version 7.3.0 patches the issue.
- Record
EUVD-2026-63989- CVSS 3.1
- 9.9 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H - Updated
- 2026-11-02
NVD
9.9
Incus is a system container and virtual machine manager. Prior to version 7.3.0, a malicious image containing a metadata.yaml symlink pointing to an arbitrary host path allows an authenticated Incus user to read or overwrite any file on the host as root via the instance metadata API. The exec-output and templates/ paths were patched in a prior release using Lstat rejection and os.OpenRoot confinement; metadata.yaml was not included in either patch and remains exploitable. Version 7.3.0 patches the issue.
- Record
CVE-2026-63343- CVSS 3.1
- 9.9 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H - Weakness
- CWE-73
- Updated
- 2026-11-02
OSV
9.9
Arbitrary File Read/Write: metadata.yaml symlink in image allows host filesystem access as root
Incus is a system container and virtual machine manager. Prior to version 7.3.0, a malicious image containing a metadata.yaml symlink pointing to an arbitrary host path allows an authenticated Incus user to read or overwrite any file on the host as root via the instance metadata API. The exec-output and templates/ paths were patched in a prior release using Lstat rejection and os.OpenRoot confinement; metadata.yaml was not included in either patch and remains exploitable. Version 7.3.0 patches the issue.
- Record
CVE-2026-63343- CVSS 3.1
- 9.9 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H - Weakness
- CWE-73
- Updated
- 2026-11-02
OSVDEBIAN-CVE-2026-63343
9.9
Incus is a system container and virtual machine manager. Prior to version 7.3.0, a malicious image containing a metadata.yaml symlink pointing to an arbitrary host path allows an authenticated Incus user to read or overwrite any file on the host as root via the instance metadata API. The exec-output and templates/ paths were patched in a prior release using Lstat rejection and os.OpenRoot confinement; metadata.yaml was not included in either patch and remains exploitable. Version 7.3.0 patches the issue.
- Record
DEBIAN-CVE-2026-63343- CVSS 3.1
- 9.9 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H - Updated
- 2026-11-02
OSVUBUNTU-CVE-2026-63343
9.9
Incus is a system container and virtual machine manager. Prior to version 7.3.0, a malicious image containing a metadata.yaml symlink pointing to an arbitrary host path allows an authenticated Incus user to read or overwrite any file on the host as root via the instance metadata API. The exec-output and templates/ paths were patched in a prior release using Lstat rejection and os.OpenRoot confinement; metadata.yaml was not included in either patch and remains exploitable. Version 7.3.0 patches the issue.
- Record
UBUNTU-CVE-2026-63343- CVSS 3.1
- 9.9 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H - Updated
- 2026-11-02
OSVopenSUSE-SU-2026:11651-1 No score
incus-7.4-1.1 on GA media
These are all security issues fixed in the incus-7.4-1.1 package on the GA media of openSUSE Tumbleweed.
- Record
openSUSE-SU-2026:11651-1- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
incusDebian:13 |
before 6.0.4-2+deb13u9, plus listed versions 6.0.4-26.0.4-2+deb13u16.0.4-2+deb13u1~bpo12+16.0.4-2+deb13u26.0.4-2+deb13u2~bpo12+1 Show 11 moreShow less6.0.4-2+deb13u36.0.4-2+deb13u3~bpo12+16.0.4-2+deb13u46.0.4-2+deb13u4~bpo12+16.0.4-2+deb13u56.0.4-2+deb13u5~bpo12+16.0.4-2+deb13u66.0.4-2+deb13u6~bpo12+16.0.4-2+deb13u76.0.4-2+deb13u7~bpo12+16.0.4-2+deb13u8 |
6.0.4-2+deb13u9 |
incusDebian:14 |
before 7.0.1-2, plus listed versions 6.0.4-26.0.4-36.0.5-16.0.5-26.0.5-3 Show 27 moreShow less6.0.5-46.0.5-56.0.5-66.0.5-76.0.5-86.0.6-16.0.6-26.0.6-36.14.0-1~exp16.15.0-1~exp16.16.0-1~exp16.17.0-1~exp16.20.0-1~exp16.21.0-1~exp16.22.0-1~exp16.23.0-1~exp17.0.0-17.0.0-1~bpo13+17.0.0-27.0.0-2~bpo13+17.0.0-37.0.0-47.0.0-57.0.0-5~bpo13+17.0.1-17.0.1-1~bpo13+17.0.1-2~bpo13+1 |
7.0.1-2 |
incusUbuntu:Pro:24.04:LTS |
All versions, plus listed versions 0.4-1ubuntu10.5.1-10.5.1-30.6-16.0.0-1 Show 7 moreShow less6.0.0-1ubuntu0.16.0.0-1ubuntu0.26.0.0-1ubuntu0.2+esm16.0.0-1ubuntu0.36.0.0-1ubuntu0.3+esm16.0.0-1ubuntu0.3+esm26.0.0-1ubuntu0.3+esm3 |
None known |
incusUbuntu:26.10 |
All versions, plus listed versions 6.0.5-87.0.1-5 |
None known |
incusUbuntu:Pro:26.04:LTS |
All versions, plus listed versions 6.0.4-26.0.5-86.0.5-8ubuntu0.26.04.1~esm1 |
None known |
incusopenSUSE:Tumbleweed |
before 7.4-1.1 | 7.4-1.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-63343 is a critical vulnerability (CVSS 9.9) in Lxc Incus, published August 21, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.48%, the 41st percentile. Fixed in incus 6.0.4-2+deb13u9.
References
github.com/lxc/incus/security/advisories/GHSA-fmjx-5j3g-997p
github.com/CVEProject/cvelistV5/tree/main/cves/2026/63xxx/CVE-2026-63343.json
nvd.nist.gov/vuln/detail/CVE-2026-63343
security-tracker.debian.org/tracker/CVE-2026-63343
ubuntu.com/security/CVE-2026-63343
cve.org/CVERecord?id=CVE-2026-63343
Show 22 moreShow less
github.com/lxc/incus/pull/3750
suse.com/security/cve/CVE-2026-39402
suse.com/security/cve/CVE-2026-47753
suse.com/security/cve/CVE-2026-48749
suse.com/security/cve/CVE-2026-48750
suse.com/security/cve/CVE-2026-48751
suse.com/security/cve/CVE-2026-48752
suse.com/security/cve/CVE-2026-48753
suse.com/security/cve/CVE-2026-48754
suse.com/security/cve/CVE-2026-48755
suse.com/security/cve/CVE-2026-48756
suse.com/security/cve/CVE-2026-48769
suse.com/security/cve/CVE-2026-55621
suse.com/security/cve/CVE-2026-55622
suse.com/security/cve/CVE-2026-62313
suse.com/security/cve/CVE-2026-62867
suse.com/security/cve/CVE-2026-62940
suse.com/security/cve/CVE-2026-62941
suse.com/security/cve/CVE-2026-63125
suse.com/security/cve/CVE-2026-63343
suse.com/security/cve/CVE-2026-81500
suse.com/security/cve/CVE-2026-81501