GHSA-vmwr-mc7x-5vc3
MEDIUMREXML denial of service vulnerability
EPSS Exploitation Probability
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
rexmlReal-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
Impact
The REXML gem before 3.3.6 has a DoS vulnerability when it parses an XML that has many deep elements that have same local name attributes.
If you need to parse untrusted XMLs with tree parser API like REXML::Document.new, you may be impacted to this vulnerability. If you use other parser APIs such as stream parser API and SAX2 parser API, this vulnerability is not affected.
Patches
The REXML gem 3.3.6 or later include the patch to fix the vulnerability.
Workarounds
Don't parse untrusted XMLs with tree parser API.
References
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 💎RubyGems | rexml | all versions | 3.3.6 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for rexml. 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 rexml to 3.3.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-vmwr-mc7x-5vc3 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 GHSA-vmwr-mc7x-5vc3 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 GHSA-vmwr-mc7x-5vc3. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-vmwr-mc7x-5vc3 in your dependencies?
O3 detects GHSA-vmwr-mc7x-5vc3 across RubyGems dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.