How severe is CVE-2023-34103?

CVE-2023-34103 has a CVSS score of 7.3/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2023-34103?

CVE-2023-34103 affects the following packages: avo (RubyGems), avo (RubyGems). Ecosystems affected: RubyGems.

How do I fix CVE-2023-34103?

Update avo to 2.33.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-34103 is resolved across your whole dependency graph.

How do I detect CVE-2023-34103 in my RubyGems dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for avo. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate CVE-2023-34103 if there is no patch (or I can't update yet)?

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.

How does O3 Security protect against CVE-2023-34103?

O3 pinpoints whether CVE-2023-34103 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is CVE-2023-34103 actively exploited in the wild?

Yes. There are 1 known exploit references for CVE-2023-34103, including 1 in-the-wild exploitation observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2023-34103?

CVE-2023-34103 has an EPSS (Exploit Prediction Scoring System) score of 0.6%, placing it in the 42th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2023-34103?

CVE-2023-34103 is classified as Cross-site Scripting (XSS) (CWE-79). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2023-34103 published, and has it been updated?

CVE-2023-34103 was published on June 5, 2023 and was last updated on April 10, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

💎 RubyGems

CVE-2023-34103

HIGH

Stored XSS (Cross Site Scripting) in html content based fields of avo

Also known asGHSA-5cr9-5jx3-2g39

Published

Jun 5, 2023

Updated

Apr 10, 2026

Affected

2 pkgs

Patched

1 / 2

Exploits

1 known

EPSS Exploitation Probability

via FIRST.org ↗

0.6%probability of exploitation in next 30 days

Lower Risk42th percentile-0.09%

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.

Blast Radius

2 pkgs affected

💎avo💎avo

Real-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

Avo is an open source ruby on rails admin panel creation framework. In affected versions some avo fields are vulnerable to Cross Site Scripting (XSS) when rendering html based content. Attackers do need form edit privilege in order to successfully exploit this vulnerability, but the results are stored and no specific timing is required. This issue has been addressed in commit 7891c01e which is expected to be included in the next release of avo. Users are advised to configure CSP headers for their application and to limit untrusted user access as a mitigation.

Affected Packages

2 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
💎RubyGems	`avo`	all versions	2.33.3
💎RubyGems	`avo`	≥ 3.0.0.pre1	No fix

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

Avo is an open source ruby on rails admin panel creation framework. In a…

github.comNVDJun 2023

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for avo. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update avo to 2.33.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-34103 is resolved across your whole dependency graph.
Workarounds
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.
How O3 protects you
O3 pinpoints whether CVE-2023-34103 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to CVE-2023-34103. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

Avo is an open source ruby on rails admin panel creation framework. In affected versions some avo fields are vulnerable to Cross Site Scripting (XSS) when rendering html based content. Attackers do need form edit privilege in order to successfully exploit this vulnerability, but the results are stored and no specific timing is required. This issue has been addressed in commit `7891c01e` which is expected to be included in the next release of avo. Users are advised to configure CSP headers for their application and to limit untrusted user access as a mitigation.

O3 Security · Impact-Aware SCA

Is CVE-2023-34103 in your dependencies?

O3 detects CVE-2023-34103 across RubyGems dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works