CVE-2024-2653 is a high-severity (CVSS 8.2) vulnerability in amphp/http. EPSS puts its 30-day exploitation probability at 83.4% (100th percentile). A fix is available for amphp/http — see the affected versions and patch details below.
CVE-2024-2653
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2024-2653.
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.
How urgent is this, really
CVE-2024-2653 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE sits: patch-first territory.
Where this sits among everything scored
Of 378,156 CVEs with a current EPSS score, this one falls in the 50–90% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
amphp/http🐘amphp/http🐘amphp/http-clientReal-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
amphp/http will collect HTTP/2 CONTINUATION frames in an unbounded buffer and will not check the header size limit until it has received the END_HEADERS flag, resulting in an OOM crash. amphp/http-client and amphp/http-server are indirectly affected if they're used with an unpatched version of amphp/http. Early versions of amphp/http-client with HTTP/2 support (v4.0.0-rc10 to 4.0.0) are also directly affected.
Acknowledgements
Thank you to Bartek Nowotarski for reporting the vulnerability.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | amphp/http | ≥ 2.0.0&&< 2.1.1 | 2.1.1composer require amphp/http:^2.1.1 |
| 🐘Packagist | amphp/http | all versions | 1.7.3composer require amphp/http:^1.7.3 |
| 🐘Packagist | amphp/http-client | ≥ 4.0.0-rc10 | No fix |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for amphp/http, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update amphp/http to 2.1.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-2653 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2024-2653 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2024-2653. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2024-2653 in your dependencies?
O3 Security finds CVE-2024-2653 across Packagist dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.