morgan up to 1.10.1/1.10.x Authorization neutralization for logs

Summaryinfo

A vulnerability was found in morgan up to 1.10.1/1.10.x. It has been classified as problematic. Affected by this vulnerability is an unknown functionality of the component Authorization Handler. The manipulation leads to neutralization for logs. This vulnerability is listed as CVE-2026-5078. The attack may be initiated remotely. There is no available exploit. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in morgan up to 1.10.1/1.10.x. This issue affects an unknown code block of the component Authorization Handler. The manipulation with an unknown input leads to a neutralization for logs vulnerability. Using CWE to declare the problem leads to CWE-117. The product does not neutralize or incorrectly neutralizes output that is written to logs. Impacted is integrity. The summary by CVE is:

Impact: The morgan logging middleware's :remote-user token extracts the Basic auth username from the Authorization request header and writes it to the log stream without neutralizing control characters. An unauthenticated attacker can send a crafted Authorization Basic header containing CR or LF bytes to inject forged log lines, breaking the one-request-per-line structure of access logs and enabling log forgery against downstream log consumers. The built-in combined, common, default, and short formats are affected, as well as any custom format that references :remote-user. Affected versions: morgan 1.2.0 through 1.10.1. Patches: upgrade to morgan 1.11.0, which neutralizes control characters in the :remote-user token output. Workarounds: use a custom format string that does not include :remote-user.

The advisory is shared at github.com. The identification of this vulnerability is CVE-2026-5078 since 03/28/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Neither technical details nor an exploit are publicly available.

Upgrading to version 1.11.0 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-34067). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Name

• morgan

Version

• 1.0
• 1.1
• 1.2
• 1.3
• 1.4
• 1.5
• 1.6
• 1.7
• 1.8
• 1.9
• 1.10
• 1.10.0
• 1.10.1

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

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• 🔒
• 🔒

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If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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