How severe is CVE-2023-26044?

CVE-2023-26044 has a CVSS score of 5.3/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2023-26044?

CVE-2023-26044 affects the following packages: react/http (Packagist). Ecosystems affected: Packagist.

How do I fix CVE-2023-26044?

Update react/http to 1.9.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-26044 is resolved across your whole dependency graph.

How do I detect CVE-2023-26044 in my Packagist dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for react/http. 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-2023-26044 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-2023-26044?

O3 pinpoints whether CVE-2023-26044 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-2023-26044 actively exploited in the wild?

No public exploit code has been indexed for CVE-2023-26044 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2023-26044?

CVE-2023-26044 has an EPSS (Exploit Prediction Scoring System) score of 0.7%, placing it in the 48th 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.

When was CVE-2023-26044 published, and has it been updated?

CVE-2023-26044 was published on May 17, 2023 and was last updated on April 2, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CVE-2023-26044: react/http Denial of Service (Medium 5.3)

EPSS Exploitation Probability

via FIRST.org ↗

0.7%probability of exploitation in next 30 days

Lower Risk48th percentile+0.25%

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

1 pkg affected

🐘react/http

Real-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

react/http is an event-driven, streaming HTTP client and server implementation for ReactPHP. Previous versions of ReactPHP's HTTP server component contain a potential DoS vulnerability that can cause high CPU load when processing large HTTP request bodies. This vulnerability has little to no impact on the default configuration, but can be exploited when explicitly using the RequestBodyBufferMiddleware with very large settings. This might lead to consuming large amounts of CPU time for processing requests and significantly delay or slow down the processing of legitimate user requests. This issue has been addressed in release 1.9.0. Users are advised to upgrade. Users unable to upgrade may keep the request body limited using RequestBodyBufferMiddleware with a sensible value which should mitigate the issue. An infrastructure or DevOps workaround could be to place a reverse proxy in front of the ReactPHP HTTP server to filter out any excessive HTTP request bodies.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`react/http`	≥ 0.8.0&&< 1.9.0	1.9.0

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for react/http. 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 react/http to 1.9.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-26044 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-2023-26044 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-2023-26044. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

react/http is an event-driven, streaming HTTP client and server implementation for ReactPHP. Previous versions of ReactPHP's HTTP server component contain a potential DoS vulnerability that can cause high CPU load when processing large HTTP request bodies. This vulnerability has little to no impact on the default configuration, but can be exploited when explicitly using the RequestBodyBufferMiddleware with very large settings. This might lead to consuming large amounts of CPU time for processing requests and significantly delay or slow down the processing of legitimate user requests. This iss

O3 Security · Impact-Aware SCA

Is CVE-2023-26044 in your dependencies?

O3 detects CVE-2023-26044 across Packagist 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

CVE-2023-26044