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Response snapshot Nov 6, 2026, 19:41 UTC

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VulnerabilityCVE-2026-28385

LXD: SSRF via image import from URL allows internal network probing by authenticated users

The LXD image import-from-URL endpoint (POST /1.0/images with source.type=url) makes server-side HTTP requests to an attacker-supplied URL without any private-IP or loopback blocking.

Published Updated

At a glance

Exploited
Not known
Severity
5.0 Medium (CVSS 3.1)
Chance of exploitation
0.3% in the next 30 days
Sources
1 source

What to do

GitHub lists first patched versions: github.com/canonical/lxd: 0.0.0-20261005133302-c4a919f3f4e2. Confirm the affected range and upgrade guidance in the exact advisory.

Read GitHub-reviewed advisory GHSA-3gq2-x4qg-p4g6 (opens a new tab)

What happened

Summary

The LXD image import-from-URL endpoint (POST /1.0/images with source.type=url) makes server-side HTTP requests to an attacker-supplied URL without any private-IP or loopback blocking. An authenticated user with the can_create_images entitlement can force the LXD daemon to connect to internal network addresses (127.0.0.

1, RFC1918 ranges, cloud metadata endpoints), enabling port scanning via error-based inference and interaction with internal HTTP services from the daemon's privileged network position.

Severity

Continue reading

- Attack Vector: Network — LXD API is network-accessible. - Attack Complexity: Low — Single crafted API request with no special conditions. - Privileges Required: Low — Requires can_create_images entitlement, a non-admin permission commonly delegated to regular users. - User Interaction: None.

- Scope: Changed — The attacker leverages LXD's privileged network position to probe and interact with internal services that are outside the attacker's direct network access and outside the scope of LXD's image management authorization. - Confidentiality Impact: Low — Error messages reveal internal port states (open/closed/filtered) and service availability.

Response bodies from internal services are NOT returned to the attacker (hash validation blocks content exfiltration). - Integrity Impact: None — No demonstrated ability to modify data on internal services. - Availability Impact: None — No meaningful resource exhaustion or denial of service.

Affected Component

- lxd/images.go — imgPostURLInfo (lines 668–755) — Makes HEAD request to user-supplied URL without any SSRF protections. - lxd/util/http.go — HTTPClient (lines 102–147) — Creates HTTP client with no IP blocking or URL validation. - shared/network.go — RFC3493Dialer (lines 20–49) — Dials arbitrary hosts including private/loopback ranges. - lxd/daemon_images.go — ImageDownload (lines 478–510, "direct" case) — Makes GET request to URL from attacker-controlled response header.

Core vulnerability: no SSRF protections on server-side image fetching

When a user imports an image from a URL, the imgPostURLInfo function makes an HTTP HEAD request directly to the user-supplied URL with zero validation:

// lxd/images.go:668-703
func imgPostURLInfo(ctx context.Context, s *state.State, req api.ImagesPost, ...) (*api.Image, error) {
 if req.Source.URL == "" {
 return nil, errors.New("Missing URL")
 }

 myhttp, err := util.HTTPClient("", s.Proxy)
 // ...

 // Resolve the image URL
 head, err := http.NewRequest("HEAD", req.Source.URL, nil)
 // No URL validation, no scheme check, no IP range check
 // ...

 raw, err := myhttp.Do(head) // Makes request to arbitrary destination

The HTTP client is created via util.HTTPClient which uses shared.RFC3493Dialer — a standard dialer with zero private-IP filtering:

// shared/network.go:20-49
func RFC3493Dialer(context context.Context, network string, address string) (net.Conn, error) {
 host, port, err := net.SplitHostPort(address)
 // ...
 addrs, err := net.LookupHost(host)
 // ...
 for _, a := range addrs {
 c, err := net.DialTimeout(network, net.JoinHostPort(a, port), 10*time.Second)
 // No check: IsLoopback? IsPrivate? IsLinkLocalUnicast?
 // Connects to ANY resolved address including 127.0.0.1, 10.x.x.x, 169.254.169.254

The HTTP client also follows redirects unconditionally:

// lxd/util/http.go:139-144
myhttp.CheckRedirect = func(req *http.Request, via []*http.Request) error {
 // Replicate the headers
 req.Header = via[len(via)-1].Header
 return nil // Always follows redirects — no destination validation
}

No SSRF protections exist anywhere in the codebase

An exhaustive search for private-IP checks (IsLoopback, IsPrivate, IsLinkLocalUnicast), URL allowlists, or SSRF-specific protections found zero results in any HTTP client or outbound request path. The codebase has no SSRF defense infrastructure.

Chained SSRF via LXD-Image-URL response header

After the HEAD request, the LXD-Image-URL response header is used as the target for a second HTTP GET request, creating a chained SSRF:

// lxd/images.go:705-725
hash := raw.Header.Get("LXD-Image-Hash") // Attacker controls this
url := raw.Header.Get("LXD-Image-URL") // Attacker controls this

info, err := ImageDownload(ctx, s, op, &ImageDownloadArgs{
 Server: url, // Attacker-controlled URL from response header
 Protocol: "direct", // Forces unprotected direct HTTP GET
 Alias: hash, // Attacker-controlled hash
 // ...
})

In ImageDownload, the "direct" case makes a GET to the attacker-controlled URL:

// lxd/daemon_images.go:478-510
case "direct":
 httpClient, err := util.HTTPClient(args.Certificate, s.Proxy)
 // ...
 req, err := http.NewRequest(http.MethodGet, args.Server, nil) // args.Server = attacker URL
 // ...
 raw, doneCh, err := cancel.CancelableDownload(canceler, httpClient.Do, req)

This means an attacker who controls the HEAD target can redirect the second GET request to any internal service. The response body is downloaded to disk but hash validation prevents the attacker from reading it:

// lxd/daemon_images.go:541-544
result := hex.EncodeToString(sha256.Sum(nil))
if result != fp {
 return nil, fmt.Errorf("Hash mismatch for %q: %s != %s", args.Server, result, fp)
}

Error observability enables port scanning

Errors from the outbound request propagate back to the caller via the operation result:

// lxd/operations/operations.go:612-614
if op.err != nil {
 retOp.Err = response.SmartError(op.err).String()
}

The error messages differ based on the target's state: - Port open: "Missing LXD-Image-Hash header" (HEAD succeeded, response had no expected headers) - Port closed: "connection refused" (connection rejected immediately) - Port filtered/host unreachable: "context deadline exceeded" / "no route to host" (timeout or routing er

Affected package ranges reported by GitHub: github.com/canonical/lxd: < 0.0.0-20261005133302-c4a919f3f4e2

Scores and how they were measured

CVSS base severity

5.0

Version 3.1As of

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

Measurement source (opens a new tab)

How bad it is if exploited. Not a prediction of exploitation or proof you are exposed.

EPSS probability

0.3%

Scored Percentile 20.3%

Model and measurement source (opens a new tab)

A model's estimate of exploitation in the next 30 days, not certainty or your own risk.

Related technology

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Sources

  1. Primary source

    GitHub-reviewed advisory GHSA-3gq2-x4qg-p4g6 (opens a new tab)

    The public advisory supplies the description, affected package/version ranges, and any listed CVSS metric. GitHub review is not local review.

    Published Checked

  2. Primary source

    GitHub public advisory API page (opens a new tab)

    The API page supplied GHSA-3gq2-x4qg-p4g6, its actual identifiers, source dates, and structured metrics.

    Published Date not suppliedChecked

  3. Primary source

    FIRST measured EPSS score (opens a new tab)

    Measured EPSS probability and percentile for CVE-2026-28385, scored 2026-11-06. This is a model estimate, not proof of exposure.

    Published Checked

Cite this record

For factual claims, cite the primary sources above; cite KEVWire for its compilation, dates, and classifications.

APA

KEVWire. (2026, November 6). LXD: SSRF via image import from URL allows internal network probing by authenticated users (CVE-2026-28385). https://kevwire.com/record/CVE-2026-28385

MLA

"LXD: SSRF via image import from URL allows internal network probing by authenticated users (CVE-2026-28385)." KEVWire, 6 Nov. 2026, kevwire.com/record/CVE-2026-28385.

Chicago

KEVWire. "LXD: SSRF via image import from URL allows internal network probing by authenticated users (CVE-2026-28385)." Last modified November 6, 2026. https://kevwire.com/record/CVE-2026-28385.

Evidence summary (plain text)

LXD: SSRF via image import from URL allows internal network probing by authenticated users (Nov 6, 2026).
The LXD image import-from-URL endpoint (POST /1.0/images with source.type=url) makes server-side HTTP requests to an attacker-supplied URL without any private-IP or loopback blocking. An authenticated user with the can_create_images entitlement can force the LXD daemon to connect to internal network addresses (127.0.0.1, RFC1918 ranges, cloud metadata endpoints), enabling port scanning via error-based inference and interaction with internal HTTP services from the daemon's privileged network position.

- Attack Vector: Network — LXD API is network-accessible.
CVSS 5.0 (version 3.1; evidence as of Nov 6, 2026; https://github.com/advisories/GHSA-3gq2-x4qg-p4g6).
EPSS 0.3% for the following 30 days, scored Nov 6, 2026 (https://api.first.org/data/v1/epss?cve=CVE-2026-28385&date=2026-11-06).
Sources:
GitHub-reviewed advisory GHSA-3gq2-x4qg-p4g6: https://github.com/advisories/GHSA-3gq2-x4qg-p4g6
GitHub public advisory API page: https://api.github.com/advisories?type=reviewed&per_page=100&sort=updated&direction=desc
FIRST measured EPSS score: https://api.first.org/data/v1/epss?cve=CVE-2026-28385&date=2026-11-06
Record ID: CVE-2026-28385.
Record origin: Ingested record.
AI evidence: Not assessed.
Known exploitation: Not assessed.
Zero-day status: Not assessed. KEV membership alone does not establish zero-day status.
About this data

This record was ingested from a data source. Retrieved: Nov 6, 2026, 19:36 UTC. Ingestion is not an independent editorial investigation.

A CISA KEV listing documents known exploitation, not necessarily a zero-day; absence from the catalog does not prove a vulnerability has never been exploited.

Technology tags indicate possible relevance, not verified exposure. Confirm the affected product, version, and configuration against your own inventory; KEVWire does not scan your systems.

A personal reading checklist on this device, not verified remediation.

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