CVE-2026-72590
CRITICALCVE-2026-72590 is a critical-severity (CVSS 9.8) CWE-93 vulnerability. O3 Security confirms whether CVE-2026-72590 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
An OS command injection vulnerability in alseambusher/crontab-ui through 0.4.2 allows an unauthenticated remote attacker to inject arbitrary cron job entries by sending a crafted GET…
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-72590.
Description
An OS command injection vulnerability in alseambusher/crontab-ui through 0.4.2 allows an unauthenticated remote attacker to inject arbitrary cron job entries by sending a crafted GET request to /crontab with URL-encoded newlines in the env_vars parameter. The handler appends the env_vars value directly to the crontab file string as '${envVars}\n' without stripping newline characters, enabling an attacker to insert arbitrary cron expressions that execute attacker-controlled commands.
Detection & mitigation playbook
VulnerabilityDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for the affected component. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Remediation status
No patched version of the affected component has shipped for CVE-2026-72590 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-72590 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-72590. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-72590 in your dependencies?
O3 detects CVE-2026-72590 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.