How severe is CVE-2018-1000078?

CVE-2018-1000078 has a CVSS score of 6.1/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2018-1000078?

CVE-2018-1000078 affects the following packages: org.jruby:jruby-stdlib (Maven), rubygems-update (RubyGems). Ecosystems affected: Maven, RubyGems.

How do I fix CVE-2018-1000078?

Update org.jruby:jruby-stdlib to 9.1.16.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2018-1000078 is resolved across your whole dependency graph.

How do I detect CVE-2018-1000078 in my Maven, RubyGems dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.jruby:jruby-stdlib, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2018-1000078 if there is no patch (or I can't update yet)?

Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Is CVE-2018-1000078 actively exploited in the wild?

No public exploit code has been indexed for CVE-2018-1000078 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2018-1000078?

CVE-2018-1000078 has an EPSS (Exploit Prediction Scoring System) score of 2.7%, placing it in the 86th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2018-1000078?

CVE-2018-1000078 is classified as Cross-site Scripting (XSS) (CWE-79). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2018-1000078 published, and has it been updated?

CVE-2018-1000078 was published on March 13, 2018 and was last updated on October 20, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

☕

☕ Maven💎 RubyGems

Not in CISA KEV

MEDIUM severity

CVE-2018-1000078 — jruby-stdlib

MEDIUMFix: rubygems/rubygems@66a28b9

CVE-2018-1000078 is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in org.jruby:jruby-stdlib. A fix is available for org.jruby:jruby-stdlib — see the affected versions and patch details below.

RubyGems Cross-site Scripting vulnerability

Also known asGHSA-87qx-g5wg-mwmj

Published

Mar 13, 2018

Updated

Oct 20, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

Exploitation data as of Oct 27, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

2.7%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs86th percentile — riskier than 86% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

2 pkgs affected

☕org.jruby:jruby-stdlib💎rubygems-update

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven, RubyGems packages — download data is not available via public APIs for these ecosystems.

Description

RubyGems version Ruby 2.2 series: 2.2.9 and earlier, Ruby 2.3 series: 2.3.6 and earlier, Ruby 2.4 series: 2.4.3 and earlier, Ruby 2.5 series: 2.5.0 and earlier, prior to trunk revision 62422 contains a Cross Site Scripting (XSS) vulnerability in gem server display of homepage attribute that can result in XSS. This attack appear to be exploitable via the victim must browse to a malicious gem on a vulnerable gem server. This vulnerability appears to have been fixed in 2.7.6.

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`org.jruby:jruby-stdlib`	all versions	9.1.16.0`org.jruby:jruby-stdlib:9.1.16.0`
💎RubyGems	`rubygems-update`	all versions	2.7.6`bundle update rubygems-update --conservative`

Affected Products

2 products · 5 configurations

debian linuxdebian

1 version

7.0

Application

rubygemsrubygems

≤ 2.5.0

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.jruby:jruby-stdlib, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.jruby:jruby-stdlib to 9.1.16.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2018-1000078 is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

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.

Red HatModerate

This issue affects the versions of rubygems as shipped with Red Hat Subscription Asset Manager 1.x. Red Hat Product Security has rated this issue as having security impact of Moderate. A future update may address this issue. For additional information, refer to the Issue Severity Classification:…

Product	Fixed in	Advisory
Red Hat Enterprise Linux 7	`ruby-0:2.0.0.648-36.el7`	RHSA-2019:2028
Red Hat Enterprise Linux 7.4 Advanced Update Support	`ruby-0:2.0.0.648-35.el7_4`	RHSA-2020:0591
Red Hat Enterprise Linux 7.5 Extended Update Support	`ruby-0:2.0.0.648-35.el7_5`	RHSA-2020:0542
Red Hat Enterprise Linux 7.6 Extended Update Support	`ruby-0:2.0.0.648-36.el7_6`	RHSA-2020:0663
Red Hat Software Collections for Red Hat Enterprise Linux 6	`rh-ruby23-ruby-0:2.3.8-69.el6`	RHSA-2018:3729
Red Hat Software Collections for Red Hat Enterprise Linux 6	`rh-ruby24-ruby-0:2.4.5-91.el6`	RHSA-2018:3730
Red Hat Software Collections for Red Hat Enterprise Linux 7	`rh-ruby25-ruby-0:2.5.3-6.el7`	RHSA-2018:3731

UbuntuMEDIUM

USN-3621-1Ubuntu

Frequently Asked Questions

O3 Security · Impact-Aware SCA

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