GHSA-h3r8-h5qw-4r35 is a high-severity (CVSS 8.3) Cross-site Scripting (XSS) vulnerability in sidekiq. 1 public exploit or proof-of-concept reference is indexed, so weaponization risk is real. A fix is available for sidekiq — see the affected versions and patch details below.
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA’s SSVC triage for GHSA-h3r8-h5qw-4r35.
EPSS Exploitation Probability
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
sidekiqReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects RubyGems packages — download data is not available via public APIs for these ecosystems.
Description
sidekiq from 7.0.4 to 7.0.7 is vulnerable to reflected cross-site scripting. A fix was released in version 7.0.8.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 💎RubyGems | sidekiq | ≥ 7.0.4&&< 7.0.8 | 7.0.8bundle update sidekiq --conservative |
Affected Products
sidekiqcontribsysResearch 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 sidekiq, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update sidekiq to 7.0.8 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-h3r8-h5qw-4r35 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.
How to detect GHSA-h3r8-h5qw-4r35
A community-maintained Nuclei template exists for this CVE. You can scan for it directly:
nuclei -id ghsa-h3r8-h5qw-4r35 -u https://target- Template
- Sidekiq < 7.0.8 - Cross-Site Scripting
- Severity
- critical
- Impact
- Unauthenticated attackers can inject malicious JavaScript through the period parameter in Sidekiq metrics endpoints, potentially stealing administrator session cookies and accessing sensitive job queue information and worker statistics.
- Remediation
- Update Sidekiq to version 7.0.8 or later that properly sanitizes the period parameter and encodes output in the metrics dashboard.
Template by ProjectDiscovery nuclei-templates (ritikchaddha, princechaddha), MIT licensed. View the full template. Scan only systems you are authorised to test.
Frequently Asked Questions
Is GHSA-h3r8-h5qw-4r35 in your dependencies?
Find it across RubyGems, including transitive dependencies.