CVE-2026-33209
Avo has a XSS vulnerability on `return_to` param
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Passive
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Avo has a XSS vulnerability on `return_to` param
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.
- Record
CVE-2026-33209- CVSS 4.0
- 5.3 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N - Weakness
- CWE-79
- Updated
- 2026-11-02
EUVDEUVD-2026-13873
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.
- Record
EUVD-2026-13873- CVSS 4.0
- 5.3 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-762r-27w2-q22j
Avo has a XSS vulnerability on `return_to` param
Description
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.
Impact
This vulnerability may allow execution of arbitrary JavaScript in the context of the application.
Impact varies depending on deployment:
- In unauthenticated setups: exploitable via crafted links sent to users
- In authenticated setups: limited to authenticated users and requires interaction
- Record
GHSA-762r-27w2-q22j- CVSS 4.0
- 5.3 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N - Weakness
- CWE-79
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2026-33209- CVSS 4.0
- 5.3 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 6.1 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
OSV
Avo has a XSS vulnerability on `return_to` param
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.
- Record
CVE-2026-33209- CVSS 4.0
- 5.3 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N - Weakness
- CWE-79
- Updated
- 2026-11-02
OSVGHSA-762r-27w2-q22j
Avo has a XSS vulnerability on `return_to` param
Description
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.
Impact
This vulnerability may allow execution of arbitrary JavaScript in the context of the application.
Impact varies depending on deployment:
- In unauthenticated setups: exploitable via crafted links sent to users
- In authenticated setups: limited to authenticated users and requires interaction
- Record
GHSA-762r-27w2-q22j- CVSS 4.0
- 5.3 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N - Weakness
- CWE-79
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
avoRubyGems |
through 3.30.2 | 3.30.3 |
avoRubyGems |
before 3.30.3, plus listed versions 0.2.00.2.10.2.20.2.30.2.4 Show 45 moreShow less0.2.50.3.10.3.20.4.10.4.100.4.20.4.30.4.40.4.50.4.60.4.70.4.80.4.90.5.0.beta10.5.0.beta100.5.0.beta110.5.0.beta120.5.0.beta130.5.0.beta140.5.0.beta150.5.0.beta20.5.0.beta30.5.0.beta40.5.0.beta50.5.0.beta60.5.0.beta70.5.0.beta80.5.0.beta91.0.01.0.11.0.21.0.41.0.51.1.01.1.0.pre.11.10.01.10.11.10.21.10.31.11.01.11.11.11.21.11.31.11.41.11.5 |
3.30.3 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-33209 is a medium vulnerability (CVSS 5.3) in Avo-hq Avo, published March 18, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.27%, the 19th percentile. Fixed in avo 3.30.3.
References
github.com/avo-hq/avo/security/advisories/GHSA-762r-27w2-q22j
nvd.nist.gov/vuln/detail/CVE-2026-33209
Left out here: 515 versions. The JSON record has them.