CVE-2023-51079 — mvel2
MEDIUMCVE-2023-51079 is a medium-severity (CVSS 5.3) vulnerability in org.mvel:mvel2. 1 public exploit reference exists, so weaponization risk is real. No vendor fix is recorded yet; mitigation options are listed below.
mvel2 TimeOut error exists in the ParseTools.subCompileExpression method
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2023-51079 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 378,567 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
org.mvel:mvel2Real-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
A long execution time can occur in the ParseTools.subCompileExpression method in MVEL 2.5.0.Final because of many Java class lookups. NOTE: the vendor disputes this because "the only thing that you could expect is that the parser will take a crazy amount of time to complete its task."
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.mvel:mvel2 | all versions | No fix |
Research 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 org.mvel:mvel2, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Remediation status
No patched version of org.mvel:mvel2 has shipped for CVE-2023-51079 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2023-51079 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2023-51079. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
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.
This CVE is disputed because the only anticipated outcome is that the parser will take an exceptionally long time to complete its task.
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat build of Apache Camel 4.4.1 for Spring Boot 3.2 | mvel | RHSA-2024:4884 |
Frequently Asked Questions
Is CVE-2023-51079 in your dependencies?
O3 Security finds CVE-2023-51079 across Maven dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.