CVE-2025-14523

What it is

A flaw in libsoup’s HTTP header handling allows multiple Host: headers in a request and returns the last occurrence for server-side processing. Common front proxies often honor the first Host: header, so this mismatch can cause vhost confusion where a proxy routes a request to one backend but the backend interprets it as destined for another host. This discrepancy enables request-smuggling style attacks, cache poisoning, or bypassing host-based access controls when an attacker supplies duplicate Host headers.

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of data tampering.

Exploit odds

0.5% chance of exploitation in the next 30 days (EPSS).

Fix

No patch or advisory is linked yet. Look at mitigations or restrict exposure.

Timeline

1. 2025-12-11 07:03 UTC ReservedThe CVE id was reserved by its CNA
2. 2025-12-11 13:15 UTC PublishedDisclosed publicly on CVE.org and NVD
3. 2026-11-04 22:17 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.5% in the next 30 days (EPSS).
• Severity: 8.2 HIGH (CVSS).
• Fix: none linked yet, which raises it.

Details

Published

2025-12-11 13:15 UTC

Last modified

2026-11-04 22:17 UTC

Exploit probability

0.5% · EPSS, next 30 days

Weakness

CWE-444

Record status

Deferred

Attack profile CVSS 3.1 · 8.2

Attack vector

Network

Complexity

Low

Privileges needed

None

User interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

High

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-2025-14523.md and follow it. Check whether this project is affected by CVE-2025-14523. 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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