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
laminas/laminas-diactoros🐘laminas/laminas-diactoros🐘laminas/laminas-diactoros🐘laminas/laminas-diactoros🐘laminas/laminas-diactoros🐘laminas/laminas-diactoros🐘laminas/laminas-diactoros🐘laminas/laminas-diactorosReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
Impact
Affected versions of Laminas Diactoros accepted a single line feed (LF / \n ) character at the end of a header name. When serializing such a header name containing a line-feed into the on-the-wire representation of a HTTP/1.x message, the resulting message would be syntactically invalid, due to the header line being terminated too early. An attacker that is able to control the header names that are passed to Laminas Diactoros would be able to intentionally craft invalid messages, possibly causing application errors or invalid HTTP requests being sent out with an PSR-18 HTTP client. The latter might present a denial of service vector if a remote service’s web application firewall bans the application due to the receipt of malformed requests.
Patches
The problem has been patched in the following versions:
- 2.18.1
- 2.19.1
- 2.20.1
- 2.21.1
- 2.22.1
- 2.23.1
- 2.24.2
- 2.25.2
Workarounds
Validate HTTP header keys and/or values, and if using user-supplied values, filter them to strip off leading or trailing newline characters before calling withHeader().
References
- CVE-2023-29197
- GHSA-wxmh-65f7-jcvw
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | laminas/laminas-diactoros | all versions | 2.18.1 |
| 🐘Packagist | laminas/laminas-diactoros | ≥ 2.19.0&&< 2.19.1 | 2.19.1 |
| 🐘Packagist | laminas/laminas-diactoros | ≥ 2.20.0&&< 2.20.1 | 2.20.1 |
| 🐘Packagist | laminas/laminas-diactoros | ≥ 2.21.0&&< 2.21.1 | 2.21.1 |
| 🐘Packagist | laminas/laminas-diactoros | ≥ 2.22.0&&< 2.22.1 | 2.22.1 |
| 🐘Packagist | laminas/laminas-diactoros | ≥ 2.23.0&&< 2.23.1 | 2.23.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for laminas/laminas-diactoros. 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 laminas/laminas-diactoros to 2.18.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-xv3h-4844-9h36 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-xv3h-4844-9h36 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-xv3h-4844-9h36. 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-xv3h-4844-9h36 in your dependencies?
O3 detects GHSA-xv3h-4844-9h36 across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.