CVE-2026-82976
Image-customization-controller: unauthenticated plaintext image server with directory listing exposes ignition images containing cluster pull secret
Description
A flaw was found in the image-customization-controller used in OpenShift's bare metal provisioning stack. The controller registers an HTTP file server on port 8084 with no authentication. The custom imageFileSystem implementation exposes a browsable HTML directory listing of all registered images at the root path. The only access control on per-host images is the random UUID filename; the directory listing discloses those UUIDs to any caller on the provisioning network. Each served image embeds an Ignition config containing the base64-encoded cluster pull secret, optional IRONIC_RAMDISK_SSH_KEY, proxy settings, and per-host NetworkManager keyfiles. An adjacent network attacker can enumerate all image UUIDs via directory listing, download any image, extract the embedded Ignition config, and recover the cluster pull secret and SSH key. ### Evidence **pkg/imagehandler/imagefilesystem.go — root directory is browsable and enumerates all UUID image names** ```go func (f *imageFileSystem) Readdir(n int) ([]fs.FileInfo, error) { f.mu.Lock() defer f.mu.Unlock() result := []fs.FileInfo{} for _, im := range f.images { result = append(result, im) } return result, nil } func (f *imageFileSystem) Open(name string) (http.File, error) { f.log.Info("Open", "path", name) if name == "/" { return f, nil } ... ``` **cmd/controller/main.go — file server bound on all interfaces without auth or TLS** ```go http.Handle("/", http.FileServer(imageServer.FileSystem())) go func() { server := &http.Server{ Addr: imagesBindAddr, // default ":8084" ReadHeaderTimeout: 5 * time.Second, } err := server.ListenAndServe() ``` **pkg/ignition/service_config.go:94-100 — pull secret is embedded in every served image** ```go func (b *ignitionBuilder) authFile() ignition_config_types_32.File { source := "data:;base64," + strings.TrimSpace(b.ironicAgentPullSecret) return ignition_config_types_32.File{ Node: ignition_config_types_32.Node{Path: "/etc/authfile.json"}, ... ``` ### Attack Pattern Adjacent provisioning-network client → GET / lists UUID image names → download ISO/initramfs → extract embedded Ignition → recover cluster pull secret and SSH key.
INFO
Published Date :
Nov. 3, 2026, 7:18 p.m.
Last Modified :
Nov. 3, 2026, 7:18 p.m.
Remotely Exploit :
No
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 53f830b8-0a3f-465b-8143-3b8a9948e749 | ||||
| CVSS 3.1 | HIGH | [email protected] |
Solution
- Implement authentication for the image-customization-controller.
- Restrict network access to the controller's port.
- Update the controller software to the latest version.
- Review image file system configurations.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
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CVE-2026-82976.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-82976 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-2026-82976
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).
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CVE-2026-82976 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-82976 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.
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New CVE Received by [email protected]
Nov. 03, 2026
Action Type Old Value New Value Added Description A flaw was found in the image-customization-controller used in OpenShift's bare metal provisioning stack. The controller registers an HTTP file server on port 8084 with no authentication. The custom imageFileSystem implementation exposes a browsable HTML directory listing of all registered images at the root path. The only access control on per-host images is the random UUID filename; the directory listing discloses those UUIDs to any caller on the provisioning network. Each served image embeds an Ignition config containing the base64-encoded cluster pull secret, optional IRONIC_RAMDISK_SSH_KEY, proxy settings, and per-host NetworkManager keyfiles. An adjacent network attacker can enumerate all image UUIDs via directory listing, download any image, extract the embedded Ignition config, and recover the cluster pull secret and SSH key. ### Evidence **pkg/imagehandler/imagefilesystem.go — root directory is browsable and enumerates all UUID image names** ```go func (f *imageFileSystem) Readdir(n int) ([]fs.FileInfo, error) { f.mu.Lock() defer f.mu.Unlock() result := []fs.FileInfo{} for _, im := range f.images { result = append(result, im) } return result, nil } func (f *imageFileSystem) Open(name string) (http.File, error) { f.log.Info("Open", "path", name) if name == "/" { return f, nil } ... ``` **cmd/controller/main.go — file server bound on all interfaces without auth or TLS** ```go http.Handle("/", http.FileServer(imageServer.FileSystem())) go func() { server := &http.Server{ Addr: imagesBindAddr, // default ":8084" ReadHeaderTimeout: 5 * time.Second, } err := server.ListenAndServe() ``` **pkg/ignition/service_config.go:94-100 — pull secret is embedded in every served image** ```go func (b *ignitionBuilder) authFile() ignition_config_types_32.File { source := "data:;base64," + strings.TrimSpace(b.ironicAgentPullSecret) return ignition_config_types_32.File{ Node: ignition_config_types_32.Node{Path: "/etc/authfile.json"}, ... ``` ### Attack Pattern Adjacent provisioning-network client → GET / lists UUID image names → download ISO/initramfs → extract embedded Ignition → recover cluster pull secret and SSH key. Added CVSS V3.1 AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N Added CWE CWE-548 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/82xxx/CVE-2026-82976.json">CVE-2026-82976</a> Added Reference https://access.redhat.com/security/cve/CVE-2026-82976 Added Reference https://bugzilla.redhat.com/show_bug.cgi?id=2526334 Added Reference https://github.com/openshift/image-customization-controller Added Reference https://redhat.atlassian.net/browse/OCPBUGS-105396