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TI-2026-27642 Aliases CVE-2026-35527GHSA-8gw4-p4wq-4hcv

Incus blind SSRF via image import preflight HEAD request

Priority MEDIUM 57CWE-918Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
—
Confidentiality · integrity · availability
None · None · None
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub.

Summary

Incus is an open source container and virtual machine manager. In versions prior to 7.0.0, the image import flow issues an outbound HEAD request to a user-supplied URL before validating the request against project restrictions such as restricted.images.servers. The imgPostURLInfo function constructs and sends a HEAD request directly from the attacker-supplied source URL to resolve image metadata, and this network interaction occurs before the flow reaches the point where the import would be rejected by policy. Although the actual image download is blocked by the project restriction, an authenticated user can coerce the daemon into making blind HEAD requests to arbitrary destinations. These requests include server metadata in custom headers (Incus-Server-Architectures, Incus-Server-Version), which discloses information about the host environment to the attacker-controlled endpoint. This blind SSRF primitive can be used to probe internal services, unroutable address space, or cloud metadata endpoints reachable from the host. This vulnerability pattern is similar to CVE-2026-24767. This issue has been fixed in version 7.0.0.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00271 19th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed incus (lxc): 7.0.0github.com/lxc/incus/v6/cmd/incusd (Go): 7.0.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
lxcincusbefore 7.0.07.0.0Patch availableCNA
—github.com/lxc/incus/v6/cmd/incusd (Go)before 7.0.07.0.0Patch availableGHSA-8gw4-p4wq-4hcv
  • incus Vendorlxc Affected before 7.0.0 Fixed in 7.0.0 Patch available CNA
  • github.com/lxc/incus/v6/cmd/incusd (Go) Vendor— Affected before 7.0.0 Fixed in 7.0.0 Patch available GHSA-8gw4-p4wq-4hcv

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:linuxcontainers:incus:*:*:*:*:*:*:*:*before 7.0.0Vulnerablelxc
  • cpe:2.3:a:linuxcontainers:incus:*:*:*:*:*:*:*:* Versions before 7.0.0 Vulnerable ·lxc

Remediation

  • Fix · CNA incus (lxc) Fixed in 7.0.0
  • Fix · GHSA-8gw4-p4wq-4hcv github.com/lxc/incus/v6/cmd/incusd (Go) Fixed in 7.0.0 Advisory →

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product
  • Red Hat

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-35527
  2. 2026-10-03 Alias added: GHSA-8gw4-p4wq-4hcv

References

Exploit 1

Advisory 1

Other 2

  • TI-2026-19296 Incus container image templating arbitrary host file read and write CVSS 3.1HIGH 8.7
  • TI-2026-19295 Incus container environment configuration newline injection CVSS 3.1HIGH 8.7
  • TI-2025-39899 Incus vulnerable to local privilege escalation through custom storage volumes CVSS 4.0HIGH 8.6
  • TI-2026-29045 Incus out-of-bounds panic in snapshot metadata handling allows denial of service CVSS 4.0HIGH 7.1
  • TI-2026-29009 Incus nil-pointer dereference in storage bucket import allows denial of service CVSS 4.0HIGH 7.1
  • TI-2026-26122 Incus vulnerable to denial of source through crafted bucket backup file CVSS 3.1MEDIUM 6.5
See all 17 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences