CVE-2020-26238 | Critical vulnerability found in cron-utils

Exp

Cron-utils is a Java library to parse, validate, migrate crons as well as get human readable descriptions for them. In cron-utils before version 9.1.3, a template Injection vulnerability is present. This enables attackers to inject arbitrary Java EL expressions, leading to unauthenticated Remote Code Execution (RCE) vulnerability. Only projects using the @Cron annotation to validate untrusted Cron expressions are affected. This issue was patched in version 9.1.3.

Published: 2020-11-24 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2020-26238 is rated High Exploit Risk (73/100): CVSS High severity, with medium exploitation likelihood (EPSS 4.20%). 2 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2020-26238

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2020-26238

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 9.96% 4.20% -5.76%
2 2026-04-01 6.49% 9.96% +3.48%
3 2025-11-21 — 6.49% —

Full EPSS history (22 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-26238

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.9 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
 1.5 5.8 [email protected]
8.1 3.1 HIGH
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.2 5.9 [email protected]
6.8 2.0 MEDIUM
AV:N/AC:M/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 8.6 6.4 [email protected]

Weakness enumeration for CVE-2020-26238

GitHub Security Advisory for CVE-2020-26238

GHSA-pfj3-56hm-jwq5 · Severity: critical · Ecosystem: maven — Template injection in cron-utils

OS Trackers for CVE-2020-26238

vendor priority summary link
redhat high — https://access.redhat.com/security/cve/CVE-2020-26238

Affected software / configurations for CVE-2020-26238

Vendor Product Version Raw CPE
cron-utils_project cron-utils < 9.1.3 cpe:2.3:a:cron-utils_project:cron-utils:*:*:*:*:*:*:*:*

References for CVE-2020-26238

URL Tags
https://github.com/jmrozanec/cron-utils/commit/4cf373f7352f5d95f0bf6512af8af326b31c835e Patch Third Party Advisory
https://github.com/jmrozanec/cron-utils/issues/461 Exploit Issue Tracking Third Party Advisory
https://github.com/jmrozanec/cron-utils/security/advisories/GHSA-pfj3-56hm-jwq5 Exploit Third Party Advisory
https://lists.apache.org/thread.html/r390bb7630b7ea8f02bf7adbbe69c0ae8b562c527d663c543d965f959%40%3Cgitbox.hive.apache.org%3E
https://lists.apache.org/thread.html/r432a69a1a85cbcb1f1bad2aa0fbfce0367bf894bf917f6ed7118e7f0%40%3Cissues.hive.apache.org%3E
https://lists.apache.org/thread.html/r50e1b5544c37e408ed7e9a958b28237b1cb9660ba2b3dba46f343e23%40%3Cissues.hive.apache.org%3E
https://lists.apache.org/thread.html/r5f601d15292e3302ad0ae0e89527029546945b1cd5837af7e838d354%40%3Cdev.hive.apache.org%3E
https://lists.apache.org/thread.html/r71083c759dc627f198571b3d48b6745fe798b1d53c34f7ef8de9e7dd%40%3Cissues.hive.apache.org%3E
https://lists.apache.org/thread.html/r737406bc17d49ffe8fe6a8828d390ee0a02e45e5a5b4f931180b9a93%40%3Cissues.hive.apache.org%3E
https://lists.apache.org/thread.html/r855aead591697dc2e85faf66c99036e49f492431940b78d4e6d895b5%40%3Cgitbox.hive.apache.org%3E
https://lists.apache.org/thread.html/r96937fc9c82f3201b59311c067e97bce71123944f93102169a95bf5c%40%3Cissues.hive.apache.org%3E
https://lists.apache.org/thread.html/r9ae9a9fb1c8e2bf95c676e7e4cd06aa04f0a3a8a9ec1a6b787afb00f%40%3Cissues.hive.apache.org%3E
https://lists.apache.org/thread.html/ra9e81244d323898dde3c979dd7df6996e4037d14a01b6629ea443548%40%3Cissues.hive.apache.org%3E
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