CVE-2026-33209 json
Avo has a XSS vulnerability on `return_to` param
published 7mo ago modified 4mo ago also GHSA-762r-27w2-q22j , EUVD-2026-13873
- cvss
- 6.1
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 19%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- rubygems avo 3.30.3
- avohq avo 3.30.3
- github.com/avo-hq/avo@4453d39 commit
- github.com/avo-hq/avo#4330 pull request
- github.com/avo-hq/avo/releases/tag/v3.30.3 release
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Check with FencerCISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 7mo ago
Exploit prediction
0.27% chance of exploitation in the next 30 days, higher than 19% of all scored CVEs (FIRST EPSS, 2026-11-09).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 5.3 | 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 |
| CNA | 4.0 | 5.3 | 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 |
| NVD | 3.1 | 6.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| rubygems | avo | <3.30.3 |
3.30.3 |
Affected products
- avo-hq avo
Classification
- Weakness
-
- CWE-79 Improper Neutralization of Input During Web Page Generation
References
-
github.com
/avo-hq/avo/pull/4330
web, issue-tracking, patch
-
github.com
/avo-hq/avo/commit/4453d39ddc6309f3bc8ada73ef21e1971112de7d
web, patch
-
github.com
/avo-hq/avo/security/advisories/GHSA-762r-27w2-q22j
web, vendor-advisory
-
github.com
/avo-hq/avo/releases/tag/v3.30.3
web, product, release-notes
-
nvd.nist.gov
/vuln/detail/CVE-2026-33209
advisory
-
github.com
/avo-hq/avo
package
-
github.com
/rubysec/ruby-advisory-db/blob/master/gems/avo/CVE-2026-33209.yml
web
Sources
- CVE List CVE-2026-33209
- GitHub Advisory GHSA-762r-27w2-q22j
- NVD CVE-2026-33209
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.