CVE-2020-26238 is a high-severity (CVSS 8.1) CWE-74 vulnerability in com.cronutils:cron-utils. 2 public exploit references exist, so weaponization risk is real. A fix is available for com.cronutils:cron-utils — see the affected versions and patch details below.
Template injection in cron-utils
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2020-26238 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 385,738 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
com.cronutils:cron-utilsReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
Description
Impact
A Template Injection was identified in cron-utils enabling attackers to inject arbitrary Java EL expressions, leading to unauthenticated Remote Code Execution (RCE) vulnerability. Versions up to 9.1.2 are susceptible to this vulnerability. Please note, that only projects using the @Cron annotation to validate untrusted Cron expressions are affected.
Patches
The issue was patched and a new version released. Please upgrade to version 9.1.3.
Workarounds
There are no known workarounds up to this moment.
References
A description of the issue is provided in issue 461
For more information
If you have any questions or comments about this advisory:
- Open an issue in cron-utils Github repository
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | com.cronutils:cron-utils | all versions | 9.1.3com.cronutils:cron-utils:9.1.3 |
Affected Products
cron-utilscron-utils_projectResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for com.cronutils:cron-utils, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update com.cronutils:cron-utils to 9.1.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-26238 is resolved across your whole dependency graph.
Workarounds
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.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Integration | see advisory | RHSA-2021:3205 |
| Red Hat Integration Camel Quarkus 2 | see advisory | RHSA-2021:3207 |
| Text-Only RHOAR | cron-utils | RHSA-2021:1004 |
Frequently Asked Questions
Is CVE-2020-26238 in your dependencies?
Find it across Maven, including transitive dependencies.