# CVE-2026-35527: LXC Incus blind SSRF in image import flow

Source: https://junglewise.ai/threats/cve-2026-35527-lxc-incus-blind-ssrf-in-image-import-flow  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-05-05. Updated: 2026-07-25  
License: CC BY 4.0 with a link back

CVE-2026-35527 · Severity: medium · CVSS 5 · Published 2026-05-05

Incus, an open-source tool for managing containers and virtual machines, contains a security flaw in how it handles image imports. An authorized user can trick the system into sending network requests to internal or external addresses that should be restricted. This could allow an attacker to map out private internal networks or steal technical details about the server's configuration and version.

Technologies: [github.com/lxc/incus (Go)](https://junglewise.ai/threats/technologies/github-com-lxc-incus), [github.com/lxc/incus/v6 (Go)](https://junglewise.ai/threats/technologies/github-com-lxc-incus-v6), [github.com/lxc/incus/v6/cmd/incusd (Go)](https://junglewise.ai/threats/technologies/github-com-lxc-incus-v6-cmd-incusd), [github.com/lxc/incus/v7 (Go)](https://junglewise.ai/threats/technologies/github-com-lxc-incus-v7). Vendors: [Go](https://junglewise.ai/threats/vendors/go).

## Quick answers

**Is CVE-2026-35527 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-35527 being exploited in the wild.

**How severe is CVE-2026-35527?** Medium severity, with a CVSS score of 5, published 5 May 2026.

**Which products and versions are affected?** github.com/lxc/incus (Go) SEMVER:introduced=0; github.com/lxc/incus/v6 (Go) SEMVER:introduced=0; github.com/lxc/incus/v6/cmd/incusd (Go) SEMVER:introduced=0,fixed=7.0.0; github.com/lxc/incus/v7 (Go) SEMVER:introduced=0,fixed=7.0.0.

**Is there a fix for CVE-2026-35527?** Yes. github.com/lxc/incus/v6/cmd/incusd (Go): upgrade to 7.0.0 or later; github.com/lxc/incus/v7 (Go): upgrade to 7.0.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-35527 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-35527?** Check whether you run github.com/lxc/incus (Go), github.com/lxc/incus/v6 (Go), github.com/lxc/incus/v6/cmd/incusd (Go) or one of the others listed at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- github.com/lxc/incus/v6/cmd/incusd (Go): upgrade to 7.0.0 or later

  ```sh
  go get github.com/lxc/incus/v6/cmd/incusd@v7.0.0
  ```

- github.com/lxc/incus/v7 (Go): upgrade to 7.0.0 or later

  ```sh
  go get github.com/lxc/incus/v7@v7.0.0
  ```


## Technical details

A blind Server-Side Request Forgery (SSRF) vulnerability exists in the `imgPostURLInfo` function of Incus. The application issues an outbound HTTP HEAD request to a user-supplied URL to resolve image metadata before validating the request against project restrictions (such as `restricted.images.servers`). While the final image download is eventually blocked by policy, the initial HEAD request is executed regardless. These requests include custom headers like `Incus-Server-Architectures` and `Incus-Server-Version`, leaking host environment details. Attackers can leverage this to probe internal services, unroutable address spaces, or cloud metadata endpoints. The issue is fixed in version 7.0.0.

## Affected products

- LXC Incus < 7.0.0

## Identifiers

- CVE-2026-35527
- GHSA-8gw4-p4wq-4hcv
- GO-2026-5254

## Timeline

- 2026-04-30: advisory: GitHub Security Advisory published
- 2026-05-05: disclosed: CVE published to NVD
- 2026-05-05: patched: Fixed in version 7.0.0

## References

- [https://github.com/lxc/incus/blob/v6.22.0/cmd/incusd/images.go](https://github.com/lxc/incus/blob/v6.22.0/cmd/incusd/images.go)
- [https://github.com/lxc/incus/security/advisories/GHSA-8gw4-p4wq-4hcv](https://github.com/lxc/incus/security/advisories/GHSA-8gw4-p4wq-4hcv)

## Related threats

- [Incus project restriction bypass in instance copy](https://junglewise.ai/threats/cve-2026-55622-incus-project-restriction-bypass-in-instance-copy)
- [Incus authorization bypass in custom volume copy](https://junglewise.ai/threats/cve-2026-55621-incus-authorization-bypass-in-custom-volume-copy)
- [LXC Incus arbitrary file write via image hash path traversal](https://junglewise.ai/threats/cve-2026-48769-lxc-incus-arbitrary-file-write-via-image-hash-path-traversal)
- [LXC Incus nil-pointer dereference in CreateCustomVolumeFromBackup](https://junglewise.ai/threats/cve-2026-48756-lxc-incus-nil-pointer-dereference-in-createcustomvolumefrombackup)
- [LXC Incus argument injection in backup compression algorithm](https://junglewise.ai/threats/cve-2026-48755-lxc-incus-argument-injection-in-backup-compression-algorithm)