GHSA-q77q-vx4q-xx6q — esapi
MEDIUMGHSA-q77q-vx4q-xx6q is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in org.owasp.esapi:esapi. 1 public exploit reference exists, so weaponization risk is real. A fix is available for org.owasp.esapi:esapi — see the affected versions and patch details below.
Cross-site Scripting in org.owasp.esapi:esapi
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
GHSA-q77q-vx4q-xx6q 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.owasp.esapi:esapiReal-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
There is a potential for an XSS vulnerability in ESAPI caused by a incorrect regular expression for "onsiteURL" in the antisamy-esapi.xml configuration file that can cause URLs with the "javascript:" scheme to NOT be sanitized. See the reference below for full details.
Patches
Patched in ESAPI 2.3.0.0 and later. See important remediation details in the reference given below.
Workarounds
Manually edit your antisamy-esapi.xml configuration files to change the "onsiteURL" regular expression as per remediation instructions in the reference below.
References
For more information
If you have any questions or comments about this advisory:
- Email one of the project co-leaders. See email addresses listed on the OWASP ESAPI wiki page, under "Leaders".
- Send email to one of the two ESAPI related Google Groups listed under Where to Find More Information on ESAPI on our README.md page.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.owasp.esapi:esapi | all versions | 2.3.0.0org.owasp.esapi:esapi:2.3.0.0 |
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.owasp.esapi:esapi, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.owasp.esapi:esapi to 2.3.0.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-q77q-vx4q-xx6q 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.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-q77q-vx4q-xx6q can be triaged on real exposure rather than presence alone.
Tailored to GHSA-q77q-vx4q-xx6q. 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.
Frequently Asked Questions
Is GHSA-q77q-vx4q-xx6q in your dependencies?
O3 Security finds GHSA-q77q-vx4q-xx6q across Maven dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.