CVE-2026-47066
7.5 · HIGHOverview
CVE-2026-47066 is a high-severity vulnerability affecting benoitc hackney. It was published on May 25, 2026 and has a CVSS 3.1 base score of 7.5 (HIGH).
This vulnerability has a CVSS 3.1 base score of 7.5, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
Technical Description
Loop with Unreachable Exit Condition ('Infinite Loop') vulnerability in benoitc hackney allows Excessive Allocation. The Alt-Svc response header parser in src/hackney_altsvc.erl does not guarantee forward progress. When parse_token/2 receives a non-token, non-whitespace, non-comma byte (e.g. !, @, =, ;), it returns the input unchanged. skip_comma/1 also returns the buffer unchanged when the first byte is not a comma. parse_entries/2 then recurses with identical data, creating a tight infinite tail-recursive loop that pins a scheduler at 100% CPU. The calling process never returns.
The entry point parse_and_cache/3 is called synchronously in the connection process on every HTTP response. A single-byte Alt-Svc: ! response header is sufficient to trigger the hang; the header is fully controlled by any HTTP origin the client connects to.
This issue affects hackney: from 2.0.0-beta.1 before 4.0.1.
Remediation
Check the references section for vendor advisories and patches from benoitc. Update hackney to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| benoitc | hackney | >= 2.0.0, < 4.0.1 | Affected |
References
Frequently Asked Questions
What is CVE-2026-47066?
CVE-2026-47066 is a high-severity vulnerability affecting benoitc hackney. It was published on May 25, 2026 and has a CVSS 3.1 base score of 7.5 (HIGH).
How severe is CVE-2026-47066?
This vulnerability has a CVSS 3.1 base score of 7.5, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2026-47066?
Check the references section for vendor advisories and patches from benoitc. Update hackney to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2026-47066?
CyberStrike's AI-powered security agents can automatically detect CVE-2026-47066 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
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