Your RSA-2048 keys break in 2030. Find every one of them before attackers do.
Maven
Not in CISA KEV
MEDIUM severity

GHSA-5h26-c766-g93v resteasy-bom

MEDIUM

GHSA-5h26-c766-g93v is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in org.jboss.resteasy:resteasy-bom. No vendor fix is recorded yet; mitigation options are listed below.

Cross-Site Scripting

Also known asCVE-2021-20293
Published
Jun 15, 2021
Updated
Feb 17, 2024
Affected
2 pkgs
Patched
None yet
Exploits
None indexed
Exploitation data as of Sep 18, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗
0.9%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs57th percentile — riskier than 57% of all scored CVEsHighest risk

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-5h26-c766-g93v 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 376,715 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

2 pkgs affected
org.jboss.resteasy:resteasy-bomorg.jboss.resteasy:resteasy-core

Real-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 reflected Cross-Site Scripting (XSS) flaw was found in RESTEasy in all versions of RESTEasy up to 4.6.0.Final, where it did not properly handle URL encoding when calling @javax.ws.rs.PathParam without any @Produces MediaType. This flaw allows an attacker to launch a reflected XSS attack. The highest threat from this vulnerability is to data confidentiality and integrity.

Affected Packages

2 total
EcosystemPackageVulnerable rangeFix
Mavenorg.jboss.resteasy:resteasy-bomall versionsNo fix
Mavenorg.jboss.resteasy:resteasy-coreall versionsNo fix

Detection & mitigation playbook

Open-source dependency
  1. Detect

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

  2. Remediation status

    No patched version of org.jboss.resteasy:resteasy-bom has shipped for GHSA-5h26-c766-g93v yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.

  3. 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.

  4. How O3 protects you

    O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-5h26-c766-g93v can be triaged on real exposure rather than presence alone.

Tailored to GHSA-5h26-c766-g93v. 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.

Red HatModerate
ProductFixed inAdvisory
RHINT Camel-K 1.6.4see advisoryRHSA-2022:1029
RHINT Service Registry 2.0.2 GAresteasy-coreRHSA-2021:4100

Frequently Asked Questions

A reflected Cross-Site Scripting (XSS) flaw was found in RESTEasy in all versions of RESTEasy up to 4.6.0.Final, where it did not properly handle URL encoding when calling @javax.ws.rs.PathParam without any @Produces MediaType. This flaw allows an attacker to launch a reflected XSS attack. The highest threat from this vulnerability is to data confidentiality and integrity.
O3 Security · Impact-Aware SCA

Is GHSA-5h26-c766-g93v in your dependencies?

O3 Security finds GHSA-5h26-c766-g93v across Maven dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

GHSA-5h26-c766-g93v: XSS (Medium 6.1) | O3 Security