Cybersecurity professionals consider CVE-2026-104795 an immediate threat requiring urgent mitigation.
Status: Received on 14 Oct 2026, 11:16 UTC
Published on: 14 Oct 2026, 11:16 UTC
CVSS Release: version 3
secalert@redhat.com
Primary
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
CVE-2026-104795: The insights-runtime-extractor runs as a privileged DaemonSet (`hostPID: true`) that scans container processes for runtime fingerprinting. When scanning a container, the coordinator: 1. **fork()s** a child process 2. **setns()** into the target container's PID and mount namespaces 3. **fchdir()** back to an orphaned FD pointing at the extractor's own root filesystem (where `/crio.sock` is hostPath-mounted) 4. Calls **only `seteuid(target_uid)`** — changing the effective UID but leaving the **real UID and saved-set-UID at 0** and **retaining the permitted capability set** 5. The `check_no_privileged_perms()` guard inspects only the Effective capability set (so it passes), and is **skipped entirely when the target runs as uid 0** 6. The `VersionExecutable` fingerprint invokes `fpr_kind_executable` with `process.command_line[0]` — the target's argv[0], read from `/proc/<pid>/cmdline` and **fully controlled by the workload** 7. `fpr_kind_executable` calls `exec.Command(executable, "--version").Output()` — executing the **workload's own binary** inside the workload's mount namespace while **ruid=0 in the host user namespace** The executed process can call `setuid(0)` to restore full root with `CAP_SYS_ADMIN`, and inherits the orphaned cwd which resolves into the extractor container's filesystem containing the host CRI-O socket. ## Affected Code ### 1. Insufficient privilege drop (Rust — extractor coordinator) **File:** `extractor/src/insights_runtime_extractor.rs` ```rust // Lines 139-146 — seteuid-only drop, guard skipped for root containers join_process_namespaces(process.pid)?; change_dir(current_dir); switch_user(*process.uid)?; if *process.uid != 0 { perms::check_no_privileged_perms() .expect("Must not have privileged permissions to run fingerprints"); } fingerprint::run_fingerprints(&config, out_dir, &process); ``` ```rust // Lines 182-185 — only effective UID changed; ruid/suid stay 0 fn switch_user(uid: u32) -> Result<(), ScannerError> { debug!("... Becoming user: {uid}"); seteuid(uid.into()).map_err(|e| ScannerError::Errno(e)) } ``` ### 2. Execution of untrusted binary (Go — fingerprint) **File:** `fingerprints/pkg/utils/file.go` ```go // Lines 75-80 — executes a path taken verbatim from workload's argv[0] func GetExecutableVersionOutput(executable string) (string, error) { out, err := exec.Command(executable, "--version").Output() if err != nil { return "", err } return string(out), nil } ``` ### 3. Workload-controlled path forwarded (Rust — version_executable) **File:** `version_executable.rs` ```rust // Lines 29-34 — workload-controlled command_line[0] forwarded to fingerprint return Some(vec![ fpr_kind_executable, out_dir.to_string(), String::from(&process.command_line[0]), String::from(&version_executable.runtime_kind_name), ]); ``` ## Attack Pattern **Attacker:** Any tenant able to schedule a pod (unprivileged, any namespace) **Victim:** The node running the insights-runtime-extractor DaemonSet **Trigger:** Automatic — the DaemonSet scans all container processes on the node **Attack sequence:** 1. Attacker creates a pod whose process name matches a configured versioned-executable pattern (`node`, `python`, `python3`, `MainThread`, or contains `java`) 2. The pod's main binary (at the path matching argv[0]) is a malicious executable that calls `setuid(0)` to restore root 3. When the insights operator triggers a scan, the DaemonSet forks, enters the attacker's mount namespace, and executes the attacker's binary with ruid=0 4. The attacker's code regains full root with `CAP_SYS_ADMIN` in the host user namespace 5. The inherited cwd contains the host CRI-O socket → full node compromise
The exploitability of CVE-2026-104795 depends on two key factors: attack complexity (the level of effort required to execute an exploit) and privileges required (the access level an attacker needs).
CVE-2026-104795 presents an accessible attack vector with minimal effort required. Restricting access controls and implementing security updates are critical to reducing exploitation risks.
A lower complexity and fewer privilege requirements make exploitation easier. Security teams should evaluate these aspects to determine the urgency of mitigation strategies, such as patch management and access control policies.
Attack Complexity (AC) measures the difficulty in executing an exploit. A high AC means that specific conditions must be met, making an attack more challenging, while a low AC means the vulnerability can be exploited with minimal effort.
Privileges Required (PR) determine the level of system access necessary for an attack. Vulnerabilities requiring no privileges are more accessible to attackers, whereas high privilege requirements limit exploitation to authorized users with elevated access.
Above is the CVSS Sub-score Breakdown for CVE-2026-104795, illustrating how Base, Impact, and Exploitability factors combine to form the overall severity rating. A higher sub-score typically indicates a more severe or easier-to-exploit vulnerability.
Below is the Impact Analysis for CVE-2026-104795, showing how Confidentiality, Integrity, and Availability might be affected if the vulnerability is exploited. Higher values usually signal greater potential damage.
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