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NVD / CVE Program· CNA GitHub_M

CVE-2026-33897: Incus vulnerable to arbitrary file read and write through pongo templates

Noroxi assessment

Priority: Monitor (action score 39/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.48% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: lxd (Debian:12) 5.0.2-5+deb12u4; incus (Debian:13) 6.0.4-2+deb13u5; lxd (Debian:13) 5.0.2+git20231211.1364ae4-9+deb13u4.

Low priority for now. Upgrade to lxd (Debian:12) 5.0.2-5+deb12u4; incus (Debian:13) 6.0.4-2+deb13u5; lxd (Debian:13) 5.0.2+git20231211.1364ae4-9+deb13u4 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

CriticalCVSS 9.9 · v3.1—No exploit Fix available
Published
Mar 26, 2026
Updated
Jun 17, 2026
EPSS
0.4% · 42th percentile

Report tools

JSON

Action score

39

Monitor

Low priority for now.

CVSS
39 / 40 · 9.9 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.4%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · GitHub_M
10.0
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

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  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

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When you'll hear from us

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  • when exploit code appears or is weaponized
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  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
linuxcontainersincus

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linuxcontainers incusbefore 6.23.0

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

  • lxc incus

    • < 6.23.0affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12lxdfrom 0—
Debian:12lxdbefore 5.0.2-5+deb12u45.0.2-5+deb12u4
Debian:13incusbefore 6.0.4-2+deb13u56.0.4-2+deb13u5
Debian:13lxdbefore 5.0.2+git20231211.1364ae4-9+deb13u45.0.2+git20231211.1364ae4-9+deb13u4
Debian:14incusbefore 6.0.6-26.0.6-2
Gogithub.com/lxc/incusfrom 0—
Gogithub.com/lxc/incusup to and including 0.7.0—
Gogithub.com/lxc/incus/v6before 6.23.06.23.0
openSUSE:Tumbleweedincusbefore 6.23-1.16.23-1.1

Same product

linuxcontainers: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-33945Abitrary file write through systemd-creds option
    38Monitor
  • CVE-2026-33898Local Incus UI web server vulnerable to nuthentication bypass
    35Monitor
  • CVE-2026-23954Incus container image templating arbitrary host file read and write
    34Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2026-33711Mar 26, 2026 · Incus vulnerable to local privilege escalation through VM screenshot path
    18Monitor
  • ← EarlierCVE-2026-33743Mar 26, 2026 · Incus vulnerable to denial of source through crafted bucket backup file
    26Monitor
  • Later →CVE-2026-35527May 5, 2026 · Incus blind SSRF via image import preflight HEAD request
    21Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
debian:incus6.0.4-2+deb13u5 · Debian:13Package registry (OSV)
debian:lxd5.0.2+git20231211.1364ae4-9+deb13u4 · Debian:13Package registry (OSV)
Go:github.com/lxc/incus/v66.23.0Package registry (OSV)
opensuse:incus6.23-1.1 · openSUSE:TumbleweedPackage registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

—

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

  • CVE-2026-338980 days apartLocal Incus UI web server vulnerable to nuthentication bypass
    35Monitor

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted

Impact can extend beyond the vulnerable component (scope changes).

Attack vector
Network
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Changed
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-1336 · Improper Neutralization of Special Elements Used in a Template Engine

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records