CVE-2026-47076

What it is

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.

At a glance

Exploitability

Can be exploited locally on the machine without logging in. High risk of data exposure.

Exploit odds

0.2% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-05-25 15:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-07-24 10:10 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.2% in the next 30 days (EPSS).
• Severity: 6.9 MEDIUM (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2026-05-25 15:16 UTC

Last modified

2026-07-24 10:10 UTC

Exploit probability

0.2% · EPSS, next 30 days

Weakness

CWE-436

Record status

Analyzed

Affected

• Benoitc Hackney < 4.0.1

Attack profile CVSS 4.0 · 6.9

Attack vector

Local

Complexity

Low

Attack requirements

Present

Privileges needed

None

User interaction

None

Confidentiality

High

Integrity

None

Availability

None

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-47076.md and follow it. Check whether this project is affected by CVE-2026-47076. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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