Unauthenticated command execution via unrestricted SpEL evaluation
Published May 17, 2026 · Updated May 17, 2026
Expression language injection in Beetl 3.20.0 through 3.20.2 allows remote attackers to execute system commands through crafted template input. SpELFunction.call parses its first argument with SpelExpressionParser and evaluates it in a StandardEvaluationContext that permits Java type access and method invocation. Exploitation requires an application to register SpELFunction and pass attacker-controlled expression text into a template; commands run with the hosting JVM process privileges.
Summary
What happened
Expression language injection in Beetl 3.20.0 through 3.20.2 allows remote attackers to execute system commands through crafted template input. SpELFunction.call parses its first argument with SpelExpressionParser and evaluates it in a StandardEvaluationContext that permits Java type access and method invocation. Exploitation requires an application to register SpELFunction and pass attacker-controlled expression text into a template; commands run with the hosting JVM process privileges.
The record
- CVE
- CVE-2026-8759
- Published
- May 17, 2026
- Updated
- May 17, 2026
- Vendor
- iBeetl
- Product
- Beetl
- Classifications
- CWE-917, CWE-20, T1059
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 17, 2026CVE publishedPublication date reported by the CVE source.
- May 17, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=3.20.0
- Affected versionversion=3.20.1
- Affected versionversion=3.20.2
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- SpELFunction Runtime execution proof of conceptproof of concept · unverified
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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