Interpretation Conflict vulnerability in benoitc hackney allows Server Side Request Forgery. hackney_url:normalize/2 URL-decodes the host component after the URL has been parsed into a #hackney_url{} record. OTP's uri_string:parse/1 and inet:parse_address/1 do not decode percent-escapes in the host, so a URL such as http://%31%32%37%2E%30%2E%30%2E%31/ is seen by a caller's allowlist validator with host %31%32%37%2E%30%2E%30%2E%31 (not an IP address), which passes the allowlist check. hackney's normalizer then decodes the host to 127.0.0.1 and opens a TCP connection to loopback. Because hackney:request/5 always calls hackney_url:normalize/2 with no opt-out, every request that takes a binary or list URL is affected. The same technique reaches cloud instance metadata services (169.254.169.254), RFC1918 networks, and any admin interface listening on localhost.
This issue affects hackney: from 0.13.0 before 4.0.1.
References
| Link | Resource |
|---|---|
| https://cna.erlef.org/cves/CVE-2026-47076.html | Third Party Advisory Patch |
| https://github.com/benoitc/hackney/commit/452620a92ec1da2e6b4862a049a2a4f04b42068f | Patch |
| https://github.com/benoitc/hackney/security/advisories/GHSA-pj7v-xfvx-wmjq | Exploit Vendor Advisory Patch |
| https://osv.dev/vulnerability/EEF-CVE-2026-47076 | Third Party Advisory Patch |
| https://github.com/benoitc/hackney/security/advisories/GHSA-pj7v-xfvx-wmjq | Exploit Vendor Advisory Patch |
Configurations
History
27 May 2026, 13:51
| Type | Values Removed | Values Added |
|---|---|---|
| References | () https://cna.erlef.org/cves/CVE-2026-47076.html - Third Party Advisory, Patch | |
| References | () https://github.com/benoitc/hackney/commit/452620a92ec1da2e6b4862a049a2a4f04b42068f - Patch | |
| References | () https://github.com/benoitc/hackney/security/advisories/GHSA-pj7v-xfvx-wmjq - Exploit, Vendor Advisory, Patch | |
| References | () https://osv.dev/vulnerability/EEF-CVE-2026-47076 - Third Party Advisory, Patch | |
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 6.5 |
| First Time |
Benoitc
Benoitc hackney |
|
| 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-pj7v-xfvx-wmjq - |
25 May 2026, 15:16
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-05-25 15:16
Updated : 2026-05-27 13:51
NVD link : CVE-2026-47076
Mitre link : CVE-2026-47076
CVE.ORG link : CVE-2026-47076
JSON object : View
Products Affected
benoitc
- hackney
