CVE-2026-33897
published 2026-03-26CVE-2026-33897: Incus is a system container and virtual machine manager. Prior to version 6.23.0, instance template files can be used to cause arbitrary read or writes as root…
PriorityP268critical9.9CVSS 3.1
AVNACLPRLUINSCCHIHAH
EPSS
0.48%
38.3th percentile
Incus is a system container and virtual machine manager. Prior to version 6.23.0, instance template files can be used to cause arbitrary read or writes as root on the host server. Incus allows for pongo2 templates within instances which can be used at various times in the instance lifecycle to template files inside of the instance. This particular implementation of pongo2 within Incus allowed for file read/write but with the expectation that the pongo2 chroot feature would isolate all such access to the instance's filesystem. This was allowed such that a template could theoretically read a file and then generate a new version of said file. Unfortunately the chroot isolation mechanism is entirely skipped by pongo2 leading to easy access to the entire system's filesystem with root privileges. Version 6.23.0 patches the issue.
Affected
10 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| canonical | lxd | >= 0 < 5.0.2-5+deb12u4 | 5.0.2-5+deb12u4 |
| canonical | lxd | >= 0 < 5.0.2+git20231211.1364ae4-9+deb13u4 | 5.0.2+git20231211.1364ae4-9+deb13u4 |
| debian | incus | < incus 6.0.6-2 (forky) | incus 6.0.6-2 (forky) |
| debian | lxd | < incus 6.0.6-2 (forky) | incus 6.0.6-2 (forky) |
| github.com | lxc_incus | 0 – 0.7.0 | — |
| github.com | lxc_incus_v6 | >= 0 < 6.23.0 | 6.23.0 |
| linuxcontainers | incus | < 6.23.0 | 6.23.0 |
| lxc | incus | < 6.23.0 | 6.23.0 |
| lxc | incus | >= 0 < 6.0.4-2+deb13u5 | 6.0.4-2+deb13u5 |
| lxc | incus | >= 0 < 6.0.6-2 | 6.0.6-2 |
Detection & IOCsextracted from sources · hover to see the quote
- →Audit Incus instance template files (pongo2 templates) for file read/write directives that reference absolute paths or path traversal sequences that could escape the instance filesystem boundary. ↗
- ·The vulnerability is local in scope — an attacker must already have control over instance template files within an Incus instance to exploit the pongo2 chroot bypass. ↗
- ·The pongo2 chroot isolation feature, which is relied upon by Incus to confine template file access to the instance filesystem, is entirely non-functional and provides no actual containment — do not rely on it as a security boundary in any Incus version prior to the patch. ↗
CVSS provenance
nvdv3.19.9CRITICALCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
osv9.9CRITICAL
vendor_debian9.9CRITICAL
vendor_redhat9.9CRITICAL
Stop checking back — get the weekly exploitation signal.
Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.
OSV
Incus vulnerable to arbitrary file read and write through pongo templates in github.com/lxc/incus
osv·2026-04-07
CVE-2026-33897 Incus vulnerable to arbitrary file read and write through pongo templates in github.com/lxc/incus
Incus vulnerable to arbitrary file read and write through pongo templates in github.com/lxc/incus
Incus vulnerable to arbitrary file read and write through pongo templates in github.com/lxc/incus
GHSA
Incus vulnerable to arbitrary file read and write through pongo templates
ghsa·2026-03-27
CVE-2026-33897 [CRITICAL] CWE-1336 Incus vulnerable to arbitrary file read and write through pongo templates
Incus vulnerable to arbitrary file read and write through pongo templates
### Summary
Instance template files can be used to cause arbitrary read or writes as root on the host server.
### Details
Incus allows for pongo2 templates within instances which can be used at various times in the instance lifecycle to template files inside of the instance. This particular implementation of pongo2 within Incus allowed for file read/write but with the expectation that the pongo2 chroot feature would isolate all such access to the instance's filesystem.
This was allowed such that a template could theoretically read a file and then generate a new version of said file.
Unfortunately the chroot isolation mechanism is entirely skipped by pongo2 leading to easy access to the entire system's filesystem
OSV
Incus vulnerable to arbitrary file read and write through pongo templates
osv·2026-03-27
CVE-2026-33897 [CRITICAL] Incus vulnerable to arbitrary file read and write through pongo templates
Incus vulnerable to arbitrary file read and write through pongo templates
### Summary
Instance template files can be used to cause arbitrary read or writes as root on the host server.
### Details
Incus allows for pongo2 templates within instances which can be used at various times in the instance lifecycle to template files inside of the instance. This particular implementation of pongo2 within Incus allowed for file read/write but with the expectation that the pongo2 chroot feature would isolate all such access to the instance's filesystem.
This was allowed such that a template could theoretically read a file and then generate a new version of said file.
Unfortunately the chroot isolation mechanism is entirely skipped by pongo2 leading to easy access to the entire system's filesystem
OSV
CVE-2026-33897: Incus is a system container and virtual machine manager
osv·2026-03-26·CVSS 9.9
CVE-2026-33897 [CRITICAL] CVE-2026-33897: Incus is a system container and virtual machine manager
Incus is a system container and virtual machine manager. Prior to version 6.23.0, instance template files can be used to cause arbitrary read or writes as root on the host server. Incus allows for pongo2 templates within instances which can be used at various times in the instance lifecycle to template files inside of the instance. This particular implementation of pongo2 within Incus allowed for file read/write but with the expectation that the pongo2 chroot feature would isolate all such access to the instance's filesystem. This was allowed such that a template could theoretically read a file and then generate a new version of said file. Unfortunately the chroot isolation mechanism is entirely skipped by pongo2 leading to easy access to the entire system's filesystem with root privileges
Red Hat
incus: pongo2: Incus: Arbitrary file read/write as root via pongo2 template chroot bypass
vendor_redhat·2026-03-26·CVSS 9.9
CVE-2026-33897 [CRITICAL] CWE-243 incus: pongo2: Incus: Arbitrary file read/write as root via pongo2 template chroot bypass
incus: pongo2: Incus: Arbitrary file read/write as root via pongo2 template chroot bypass
Incus is a system container and virtual machine manager. Prior to version 6.23.0, instance template files can be used to cause arbitrary read or writes as root on the host server. Incus allows for pongo2 templates within instances which can be used at various times in the instance lifecycle to template files inside of the instance. This particular implementation of pongo2 within Incus allowed for file read/write but with the expectation that the pongo2 chroot feature would isolate all such access to the instance's filesystem. This was allowed such that a template could theoretically read a file and then generate a new version of said file. Unfortunately the chroot isolation mechanism is entirely skip
Debian
CVE-2026-33897: incus - Incus is a system container and virtual machine manager. Prior to version 6.23.0...
vendor_debian·2026·CVSS 9.9
CVE-2026-33897 [CRITICAL] CVE-2026-33897: incus - Incus is a system container and virtual machine manager. Prior to version 6.23.0...
Incus is a system container and virtual machine manager. Prior to version 6.23.0, instance template files can be used to cause arbitrary read or writes as root on the host server. Incus allows for pongo2 templates within instances which can be used at various times in the instance lifecycle to template files inside of the instance. This particular implementation of pongo2 within Incus allowed for file read/write but with the expectation that the pongo2 chroot feature would isolate all such access to the instance's filesystem. This was allowed such that a template could theoretically read a file and then generate a new version of said file. Unfortunately the chroot isolation mechanism is entirely skipped by pongo2 leading to easy access to the entire system's filesystem with root privileges
No detection rules found.
No public exploits indexed.
Bugzilla
CVE-2026-33897 incus: Incus: Arbitrary file read/write as root via pongo2 template chroot bypass [fedora-43]
bugzilla·2026-03-26·CVSS 9.9
CVE-2026-33897 [CRITICAL] CVE-2026-33897 incus: Incus: Arbitrary file read/write as root via pongo2 template chroot bypass [fedora-43]
CVE-2026-33897 incus: Incus: Arbitrary file read/write as root via pongo2 template chroot bypass [fedora-43]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
Discussion:
FEDORA-2026-5af38b7ecb (incus-6.23-1.fc43) has been submitted as an update to Fedora 43.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-5af38b7ecb
---
FEDORA-2026-5af38b7ecb has been pushed to the Fedora 43 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2026-5af38b7ecb`
You can provide feedback for this update here: https://b
Bugzilla
CVE-2026-33897 incus: Incus: Arbitrary file read/write as root via pongo2 template chroot bypass [fedora-42]
bugzilla·2026-03-26·CVSS 9.9
CVE-2026-33897 [CRITICAL] CVE-2026-33897 incus: Incus: Arbitrary file read/write as root via pongo2 template chroot bypass [fedora-42]
CVE-2026-33897 incus: Incus: Arbitrary file read/write as root via pongo2 template chroot bypass [fedora-42]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
Discussion:
FEDORA-2026-a9017d0297 (incus-6.23-1.fc42) has been submitted as an update to Fedora 42.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-a9017d0297
---
FEDORA-2026-a9017d0297 has been pushed to the Fedora 42 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2026-a9017d0297`
You can provide feedback for this update here: https://b
Wiz
CVE-2026-33897 Impact, Exploitability, and Mitigation Steps | Wiz
blogs_wiz·CVSS 9.9
CVE-2026-33897 [CRITICAL] CVE-2026-33897 Impact, Exploitability, and Mitigation Steps | Wiz
## CVE-2026-33897 :
Homebrew vulnerability analysis and mitigation
Incus is a system container and virtual machine manager. Prior to version 6.23.0, instance template files can be used to cause arbitrary read or writes as root on the host server. Incus allows for pongo2 templates within instances which can be used at various times in the instance lifecycle to template files inside of the instance. This particular implementation of pongo2 within Incus allowed for file read/write but with the expectation that the pongo2 chroot feature would isolate all such access to the instance's filesystem. This was allowed such that a template could theoretically read a file and then generate a new version of said file. Unfortunately the chroot isolation mechanism is entirely skipped by pongo2 leading
2026-03-26
Published