GHSA-gv3v-92v6-m48j is a critical-severity (CVSS 9.8) vulnerability in io.jooby:jooby-netty. 1 public exploit reference exists, so weaponization risk is real. O3 Security confirms whether GHSA-gv3v-92v6-m48j is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Improper Neutralization of CRLF Sequences in HTTP Headers in Jooby ('HTTP Response Splitting)
Real-World Exposure
io.jooby:jooby-nettyReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
Description
Impact
- Cross Site Scripting
- Cache Poisoning
- Page Hijacking
Patches
This was fixed in version 2.2.1.
Workarounds
If you are unable to update, ensure that user supplied data isn't able to flow to HTTP headers. If it does, pre-sanitize for CRLF characters.
References
CWE-113: Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Response Splitting')
I've been poking at libraries to see if they are vulnerable to HTTP Response Splitting and Jooby is my third case of finding this vulnerability.
Root Cause
This roots cause back to this line in the Jooby codebase:
The DefaultHttpHeaders takes a parameter validate which, when true (as it is for the no-arg constructor) validates that the header isn't being abused to do HTTP Response Splitting.
Reported By
This vulnerability was reported by @JLLeitschuh (Twitter)
For more information
If you have any questions or comments about this advisory:
- Open an issue in jooby-project/jooby
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | io.jooby:jooby-netty | all versions | 2.2.1 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for io.jooby:jooby-netty. 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 io.jooby:jooby-netty to 2.2.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-gv3v-92v6-m48j 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-gv3v-92v6-m48j 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-gv3v-92v6-m48j. 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-gv3v-92v6-m48j in your dependencies?
O3 detects GHSA-gv3v-92v6-m48j across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.