Avo is a framework to create admin panels for Ruby on Rails apps. Prior to version 3.30.3, a reflected cross-site scripting (XSS) vulnerability exists in the return_to query parameter used in the avo interface. An attacker can craft a malicious URL that injects arbitrary JavaScript, which is executed when he clicks a dynamically generated navigation button. This issue has been patched in version 3.30.3.
CVE-2026-33209
This medium-severity CVE scores 6.1 under NVD CVSS v3. EPSS exploit probability: 0.3%, top 82% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
- Lower severity and no public exploit yet
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 6.1
- EG Score
- 6.1(medium)
- EG Risk
- 32(Track)EG Risk 32/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity61% × 45%Exploitation0% × 40%Automatability30% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 0%
- EPSS %ILE
- 19%
- KEV
- Not listed
Published
March 20, 2026
Last Modified
June 17, 2026
Advisory Details (4)
Auto-updated Aug 6, 2026XSS vulnerability on return_to param · Advisory · avo-hq/avo · GitHub
https://github.com/avo-hq/avo/security/advisories/GHSA-762r-27w2-q22jRelease v3.30.3
Patch available: avo-hq/avo v3.30.3
https://github.com/avo-hq/avo/releases/tag/v3.30.3fix: `return_to` parameter
Patch available: avo-hq/avo v4.0.0.beta.8 (PR #4330 merged 2026-03-17)
https://github.com/avo-hq/avo/pull/4330commit 4453d39ddc63 (avo-hq/avo)
Patch available: avo-hq/avo v4.0.0.beta.8 (contains commit 4453d39ddc63)
https://github.com/avo-hq/avo/commit/4453d39ddc6309f3bc8ada73ef21e1971112de7dAffected Packages
(1 across 1 ecosystem)
RubyGems(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| avo | 0.2.0 ... 3.9.2 (565 versions) | 3.30.3 | — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 8× in last 7d / 31× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
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- 2026-08-25 13:49 UTCEPSS rescore
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- 2026-08-16 10:59 UTCEG score recompute
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- 2026-07-27 14:33 UTCEG score recompute
- 2026-07-27 14:27 UTCOSV refresh
Frequently asked(5)
What is CVE-2026-33209?
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Is CVE-2026-33209 actively exploited?
What is the CVSS score of CVE-2026-33209?
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Dependency Blast Radius
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