CVE-2019-3877

What it is

A vulnerability was found in mod_auth_mellon before v0.14.2. An open redirect in the logout URL allows requests with backslashes to pass through by assuming that it is a relative URL, while the browsers silently convert backslash characters into forward slashes treating them as an absolute URL. This mismatch allows an attacker to bypass the redirect URL validation logic in apr_uri_parse function.

At a glance

Exploitability

Can be exploited over the network without logging in. Limited direct impact.

Exploit odds

2.1% chance of exploitation in the next 30 days (EPSS).

Fix

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

Timeline

1. 2019-03-27 13:29 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 02:35 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 2.1% in the next 30 days (EPSS).
• Severity: 5.8 MEDIUM (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2019-03-27 13:29 UTC

Last modified

2026-06-17 02:35 UTC

Exploit probability

2.1% · EPSS, next 30 days

Weakness

CWE-601

Record status

Modified

Affected

• Mod Auth Mellon Project Mod Auth Mellon < 0.14.2
• Fedoraproject Fedora 29
• Redhat Enterprise Linux 7.0
• Canonical Ubuntu Linux 18.04
• Canonical Ubuntu Linux 18.10

Attack profile CVSS 3.0 · 5.8

Attack vector

Network

Complexity

Low

Privileges needed

None

User interaction

None

Scope

Changed

Confidentiality

None

Integrity

Low

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-2019-3877.md and follow it. Check whether this project is affected by CVE-2019-3877. 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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