CVE-2026-47066

  1. OpenCVE
  2. Vulnerabilities (CVE)
  3. CVE-2026-47066
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.

7.5 /10

CVSS v3 : HIGH

V3 Legend

Vector :

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References
Link Resource
https://cna.erlef.org/cves/CVE-2026-47066.html Third Party Advisory Patch
https://github.com/benoitc/hackney/commit/e548aba1f97ffa3f4750da7b772998fb78c01894 Patch
https://github.com/benoitc/hackney/security/advisories/GHSA-6cp8-v795-jr2j Exploit Vendor Advisory Patch
https://osv.dev/vulnerability/EEF-CVE-2026-47066 Third Party Advisory Patch
https://github.com/benoitc/hackney/security/advisories/GHSA-6cp8-v795-jr2j Exploit Vendor Advisory Patch
Configurations

Configuration 1 (hide)

cpe:2.3:a:benoitc:hackney:*:*:*:*:*:*:*:*
History

27 May 2026, 13:54

Type Values Removed Values Added
CVSS v2 : unknown
v3 : unknown 		v2 : unknown
v3 : 7.5
First Time Benoitc
Benoitc hackney
References () https://cna.erlef.org/cves/CVE-2026-47066.html - () https://cna.erlef.org/cves/CVE-2026-47066.html - Third Party Advisory, Patch
References () https://github.com/benoitc/hackney/commit/e548aba1f97ffa3f4750da7b772998fb78c01894 - () https://github.com/benoitc/hackney/commit/e548aba1f97ffa3f4750da7b772998fb78c01894 - Patch
References () https://github.com/benoitc/hackney/security/advisories/GHSA-6cp8-v795-jr2j - () https://github.com/benoitc/hackney/security/advisories/GHSA-6cp8-v795-jr2j - Exploit, Vendor Advisory, Patch
References () https://osv.dev/vulnerability/EEF-CVE-2026-47066 - () https://osv.dev/vulnerability/EEF-CVE-2026-47066 - Third Party Advisory, Patch
CPE cpe:2.3:a:benoitc:hackney:*:*:*:*:*:*:*:*

26 May 2026, 17:16

Type Values Removed Values Added
References () https://github.com/benoitc/hackney/security/advisories/GHSA-6cp8-v795-jr2j - () https://github.com/benoitc/hackney/security/advisories/GHSA-6cp8-v795-jr2j -

25 May 2026, 15:16

Type Values Removed Values Added
New CVE
Information

Published : 2026-05-25 15:16

Updated : 2026-05-27 13:54

NVD link : CVE-2026-47066

Mitre link : CVE-2026-47066

CVE.ORG link : CVE-2026-47066

JSON object : View

Products Affected

benoitc

  • hackney
CWE
CWE-835

Loop with Unreachable Exit Condition ('Infinite Loop')