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
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
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