CVE-2026-45723

managementServer.CreateSchematic (internal/backend/grpc/schematics.go) passes the caller-controlled TalosVersion field directly to imageFactoryClient.OverlaysVersions, which embeds it verbatim into a fmt.Sprintf("/version/%s/overlays/official", talosVersion) path template. url.URL.JoinPath resolves any ../ sequences in that path, allowing an authenticated Operator to rewrite the URL path and force Omni to issue HTTP GET requests to unintended paths on the configured image-factory server. Error body content from those unintended endpoints is returned to the caller.

Severity

• Attack Vector: Network: exploited via the gRPC CreateSchematic API endpoint.
• Attack Complexity: Low: once the attacker holds an Operator credential and has identified a media ID with an overlay, exploitation is a single API call.
• Privileges Required: High: role.Operator is required, which has administrative capabilities on Omni.
• User Interaction: None.
• Scope: Unchanged: the traversal is constrained to the configured image-factory host; the attacker cannot redirect Omni to an arbitrary external server.
• Confidentiality Impact: Low: error body content from unintended image-factory endpoints is reflected back to the operator, potentially leaking server-internal information.
• Integrity Impact: None: only HTTP GET requests are issued; no write operations are performed.
• Availability Impact: None.

Credit

This vulnerability was discovered and reported by bugbunny.ai.

• Same-host path traversal: An authenticated Operator can force Omni to issue GET requests to arbitrary URL paths on the configured image-factory server, bypassing the intended versioned overlay API structure.
• Error-body disclosure: HTTP error responses from unintended image-factory endpoints are reflected back to the operator, potentially leaking server-internal diagnostics or sensitive path content.
• Internal network probing: In deployments using a private image-factory instance on an internal network, the attacker can probe endpoint existence and partial responses through error-text differences.
• Depth control: By varying the number of ../ prefixes in talosVersion, the attacker can reach any path hierarchy on the image-factory host.

The application does not adequately validate input before processing it, allowing unexpected values to reach sensitive code paths. Typical impact: varies by context: data corruption, logic bypass, or denial of service.

CVE-2026-45723 has a CVSS score of 2.7 (Low). The vector is network-reachable, high privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (1.6.6, 1.7.3); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is CVE-2026-45723? CVE-2026-45723 is a low-severity improper input validation vulnerability in github.com/siderolabs/omni (go), affecting versions < 1.6.6. It is fixed in 1.6.6, 1.7.3. The application does not adequately validate input before processing it, allowing unexpected values to reach sensitive code paths.
2. How severe is CVE-2026-45723? CVE-2026-45723 has a CVSS score of 2.7 (Low). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of github.com/siderolabs/omni are affected by CVE-2026-45723? github.com/siderolabs/omni (go) versions < 1.6.6 is affected.
4. Is there a fix for CVE-2026-45723? Yes. CVE-2026-45723 is fixed in 1.6.6, 1.7.3. Upgrade to this version or later.
5. Is CVE-2026-45723 exploitable, and should I be worried? Whether CVE-2026-45723 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-45723 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-45723?
   • Upgrade github.com/siderolabs/omni to 1.6.6 or later
   • Upgrade github.com/siderolabs/omni to 1.7.3 or later