CVE-2026-43504: prosody Auth Bypass — Fix

Description

An issue was discovered in Prosody before 0.12.6 and 1.0.0 through 13.0.0 before 13.0.5, when mod_proxy65 is enabled. Because mod_proxy65 mishandles access control in a paused scenario, relaying of unauthenticated traffic can occur.

Is your site exposed to CVE-2026-43504?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

6.5

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L

EPSS — Exploit Prediction

0.0002

Probability of exploitation

0.06%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-863 Incorrect Authorization

Affected Products

Vendor	Product	Versions
prosody	prosody	< 0.12.6
prosody	prosody	13.0.0 — 13.0.5

References

Advisories & Patches

https://prosody.im/security/advisory_735dd9d3/ https://www.openwall.com/lists/oss-security/2026/05/01/5

Frequently Asked Questions

What is CVE-2026-43504? +

An issue was discovered in Prosody before 0.12.6 and 1.0.0 through 13.0.0 before 13.0.5, when mod_proxy65 is enabled. Because mod_proxy65 mishandles access control in a paused scenario, relaying of unauthenticated traffic can occur. It has a CVSS v3.1 base score of 6.5 (MEDIUM).

How severe is CVE-2026-43504? +

CVE-2026-43504 has a CVSS v3.1 score of 6.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0002, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-43504? +

CVE-2026-43504 affects products from prosody, specifically: prosody. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-43504? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2026-50008

Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. From version …

CVE-2026-42571

Pelican is a platform for creating data federations. From versions 7.21.0 to before 7.21.5, 7.22.0 to before 7.22.3, 7.23.0 to …

CVE-2026-42137

Kirby is an open-source content management system. Prior to versions 4.9.0 and 5.4.0, `pages.access/list` and `files.access/list` permissions are not consistently …

CVE-2026-54358

An incorrect authorization vulnerability in MISP allows an organization administrator to target site administrator accounts belonging to the same organization …

CVE-2026-42160

Data Space Portal is an open-source Software as a Service (SaaS) solution designed to streamline Dataspace management. From version 2.1.1 …

CVE-2026-42604

Actual is a local-first personal finance tool. The `POST /openid/config` endpoint in Actual Budget's sync-server versions <= 26.4.0 exposes the …

CVE-2026-43504