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© 2026 FAUCET Technologies LLC. All rights reserved.

CVE-2026-5078

27
FAUCET Score

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.

First published: Jun 3, 2026Last modified: Jun 3, 2026

Impacted Technologies

VendorProductVersion(s)CPE
>= 1.2.0, < 1.11.0CPE matchmatch criteria
cpe:2.3:a:morgan_project:morgan:*:*:*:*:*:node.js:*:*

CVSS Data

CVSS version used by this source: 3.1

5.3MEDIUM

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

Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
LOW
Availability Impact
NONE
Exploitability Score
3.9
Impact Score
1.4
CvssVersion
3.1

Exploit Intelligence

EPSS Score
0.33%
Probability of exploitation in next 30 days
EPSS Percentile
24.9%
Percentile rank of EPSS score among Peer Group
As of 2026-07-26
Model: v2026.06.15
This CVE's current EPSS score of 0.0032 is in the 14th percentile among its peer group of 23,705 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.1 Bluesky, 0.0 Mastodon, and 0.4 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.0 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (2)

npmpatch availablevia ghsa
Product: morganFixed in: 1.11.0
github_advisoryworkaround availablevia nvd_reference
View patch

Vendor Advisories (1)

npmGHSA-4vj7-5mj6-jm8mmedium

morgan vulnerable to Log Forging via unneutralized control characters in :remote-user

Jul 10, 2026

References

cna.openjsf.org / security-advisories.html
Third Party Advisory
github.com / expressjs/morgan/security/advisories/GHSA-4vj7-5mj6-jm8m
MitigationVendor Advisory