CVE-2026-35527
Incus blind SSRF via image import preflight HEAD request
Description
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.
INFO
Published Date :
May 5, 2026, 9:16 p.m.
Last Modified :
May 7, 2026, 5:06 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 4.0 | MEDIUM | [email protected] |
Solution
- Update Incus to version 7.0.0 or later.
- Apply vendor patches if updating is not possible.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-35527.
| URL | Resource |
|---|---|
| https://github.com/lxc/incus/blob/v6.22.0/cmd/incusd/images.go | Product |
| https://github.com/lxc/incus/security/advisories/GHSA-8gw4-p4wq-4hcv | Exploit Vendor Advisory |
| https://github.com/lxc/incus/security/advisories/GHSA-8gw4-p4wq-4hcv | Exploit Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-35527 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-35527
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-35527 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-35527 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
May. 07, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N Added CPE Configuration OR *cpe:2.3:a:linuxcontainers:incus:*:*:*:*:*:*:*:* versions up to (excluding) 7.0.0 Added Reference Type GitHub, Inc.: https://github.com/lxc/incus/blob/v6.22.0/cmd/incusd/images.go Types: Product Added Reference Type CISA-ADP: https://github.com/lxc/incus/security/advisories/GHSA-8gw4-p4wq-4hcv Types: Exploit, Vendor Advisory Added Reference Type GitHub, Inc.: https://github.com/lxc/incus/security/advisories/GHSA-8gw4-p4wq-4hcv Types: Exploit, Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
May. 06, 2026
Action Type Old Value New Value Added Reference https://github.com/lxc/incus/security/advisories/GHSA-8gw4-p4wq-4hcv -
New CVE Received by [email protected]
May. 05, 2026
Action Type Old Value New Value Added Description 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. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:L/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CWE CWE-918 Added Reference https://github.com/lxc/incus/blob/v6.22.0/cmd/incusd/images.go Added Reference https://github.com/lxc/incus/security/advisories/GHSA-8gw4-p4wq-4hcv