CVE-2026-115700

What it is

Interpretation Conflict vulnerability in hackney_url in benoitc hackney allows Server Side Request Forgery via a percent-encoded bracketed IPv6 literal or an IP literal with a trailing dot. A host such as %5B%3A%3Affff%3A127%2E0%2E0%2E1%5D (decoding to [::ffff:127.0.0.1]) or 127.0.0.1. is not an IP address to a caller's allowlist built on uri_string:parse/1 and inet:parse_address/1, while hackney connects to the address it denotes. The same applies to a Location target when redirects are followed. The IP-literal gate that hackney_url:normalize/2 applies to a percent-decoded host, added to close the percent-encoded IP bypass of CVE-2026-47076, passes the decoded value to inet_parse:address/1 as is. The connect path in hackney_happy:parse_address/1 drops a surrounding bracket pair, and the resolver ignores a trailing dot, so both forms pass the gate and still reach the literal address. Domain names with a trailing dot and unencoded IPv6 literals are not affected. This issue affects hackney: from 4.0.1 before 4.9.0.

At a glance

Exploitability

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

Exploit odds

0.1% chance of exploitation in the next 30 days (EPSS).

Fix

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

Timeline

1. 2026-10-25 17:30 UTC ReservedThe CVE id was reserved by its CNA
2. 2026-10-26 14:16 UTC PublishedDisclosed publicly on CVE.org and NVD
3. 2026-11-02 21:17 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.1% in the next 30 days (EPSS).
• Severity: 6.9 MEDIUM (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2026-10-26 14:16 UTC

Last modified

2026-11-02 21:17 UTC

Exploit probability

0.1% · EPSS, next 30 days

Weakness

CWE-436

Record status

Awaiting Analysis

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-2026-115700.md and follow it. Check whether this project is affected by CVE-2026-115700. 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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