Bug 2484311 (CVE-2026-5078) - CVE-2026-5078 morgan: morgan: Log forgery due to unneutralized control characters
Summary: CVE-2026-5078 morgan: morgan: Log forgery due to unneutralized control charac...
Keywords:
Status: NEW
Alias: CVE-2026-5078
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-06-03 08:01 UTC by OSIDB Bzimport
Modified: 2026-06-10 21:12 UTC (History)
32 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Embargoed:


Attachments (Terms of Use)

Description OSIDB Bzimport 2026-06-03 08:01:18 UTC
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.


Note You need to log in before you can comment on or make changes to this bug.